A production system and method for cold feeding a RAP charge

Abstract

The application discloses a production system and a production method of RAP material cold pouring and stacking, a hot material bin, a RAP material buffer bin and a hot aggregate scale, and adopts road RAP material to replace part of virgin aggregate, fully utilizes residual asphalt in the RAP material, realizes recycling of the RAP material, saves cost, reduces environmental pollution, meets urgent requirements of resource-saving and environment-friendly industry construction, has remarkable economic benefits and social benefits, and can realize layering of the hot aggregate and the RAP material in the hot aggregate scale after grading and grading of the hot aggregate and the RAP material, realize layering coating of the hot aggregate and the RAP material through alternation and accumulation of the hot aggregate scale and the RAP material scale in the hot aggregate and RAP material stacking measurement process, realize accurate and controllable measurement of the hot aggregate and the RAP material, make up the defect of inaccurate measurement of the previous external adding system, realize grading and time feeding of the hot aggregate according to actual grades, and realize grading and time feeding of the RAP material, so that the RAP material is ensured to be completely coated with the hot aggregate, the two kinds of materials are formed into stacking and accumulated fusion, pre-mixing and pre-heating are realized, and high-quality production of the asphalt mixture is effectively ensured.

Description

Technical Field

[0001] This invention relates to the field of asphalt concrete production technology, specifically to a production system and method for cold-poured and stacked RAP material. Background Technology

[0002] According to the Ministry of Transport's overall road construction plan, road construction will shift from a construction-oriented model to a maintenance-oriented model around 2035. With the rapid development of highway construction in my country, there are increasingly more major and medium-sized road repair and expansion projects, generating a large amount of RAP material, of which 0-5mm RAP material accounts for more than 50%. Currently, RAP material is generally recycled using cold recycling and plant-mixed hot recycling technologies. Both plant-mixed cold recycling and in-situ cold recycling are generally applied to the base or subbase of road surfaces. Especially when RAP material is recycled and applied to the base layer, its economic benefits are difficult to realize, and it may even result in waste. Plant-mixed hot recycling requires the addition of recycling rollers, which are expensive. For projects with small amounts of RAP material, this increases production costs and results in poor economic benefits.

[0003] With the significant increase in the annual volume of milled material, the RAP (Rapid Appreciation and Propagation) market for asphalt surface courses will inevitably form a long-term stable cyclical market. The application of RAP material has become the mainstream market for asphalt construction and will inevitably affect the future of asphalt pavement construction. Among them, the ability to refine RAP material directly affects the amount of RAP material added and the quality of the finished asphalt mixture, and even more directly affects the cost of asphalt mixture and the ability to produce high-quality products.

[0004] Conventional asphalt mixing plants, equipped with only one drying drum, cannot perform heated recycling of RAP material. The emergence of cold-feed technology has made it possible for conventional engineering plants to use RAP material, but in this system, the RAP material is directly mixed with the virgin material in the mixing pot. The temperature exchange time is short and it is difficult to distribute it evenly. This makes it impossible to achieve stable control, resulting in asphalt mixtures that are prone to clumping, under-mixing, and uneven temperature and gradation. Consequently, the asphalt mixtures produced have poor road performance and cannot be used in the middle and upper layers of asphalt with high quality. Summary of the Invention

[0005] The purpose of this invention is to provide a production system and method for cold-feeding and layering of RAP material, in order to solve the technical problem in the prior art where RAP material is directly mixed with virgin material in a mixing pot during the production of recycled asphalt. This results in short temperature exchange time, difficulty in uniform distribution, and inability to achieve stable control, leading to asphalt mixtures prone to clumping, under-mixing, and uneven temperature and gradation. Consequently, the produced asphalt mixtures have poor road performance and cannot be used in the middle and upper layers of asphalt with high quality.

[0006] The technical problem to be solved by this invention can be achieved through the following technical solution:

[0007] A production system and method for cold-feeding and stacking RAP material, comprising:

[0008] A hot aggregate bin is provided, with a vibrating screen installed above it and a hot aggregate elevator installed on one side of the vibrating screen.

[0009] RAP material buffer silo, RAP material elevator is installed on one side of RAP material buffer silo, and RAP material scale is installed below RAP material buffer silo;

[0010] The hot aggregate scale has its conveying end of the hot aggregate bin corresponding to its inlet end, and the RAP scale has its conveying end corresponding to its inlet end. A mixing pot is located below the hot aggregate scale, with its conveying end corresponding to the inlet end of the mixing pot.

[0011] As a further aspect of the present invention: the conveying end of the hot aggregate elevator is configured to correspond to the feeding end of the vibrating screen, and the conveying end of the vibrating screen is configured to correspond to the feeding end of the hot aggregate bin.

[0012] As a further embodiment of the present invention: the conveying end of the RAP material elevator is set to correspond to the feeding end of the RAP material buffer bin, and the conveying end of the RAP material buffer bin is set to correspond to the feeding end of the RAP material scale.

[0013] As a further embodiment of the present invention, it also includes a powder tank and an asphalt storage tank, with a powder scale installed below the powder tank and an asphalt scale installed below the asphalt storage tank.

[0014] As a further embodiment of the present invention: the conveying end of the powder tank is correspondingly set to the feeding end of the powder scale, the conveying end of the powder scale is correspondingly set to the feeding end of the mixing pot, the conveying end of the asphalt storage tank is correspondingly set to the feeding end of the asphalt scale, and the conveying end of the asphalt scale is correspondingly set to the feeding end of the mixing pot.

[0015] A method for cold-feeding and stacking RAP material includes the following steps:

[0016] Step 1: The heated hot aggregate raw materials are conveyed to the vibrating screen through the hot aggregate elevator. The heating temperature of the raw aggregate is 190℃-200℃. The vibrating screen screens the hot aggregate raw materials. The screened hot aggregate raw materials enter the hot aggregate bin for storage. The hot aggregate raw materials are divided into hot aggregate A1, hot aggregate A2, hot aggregate A3, hot aggregate A4, hot aggregate A5... hot aggregate An by adding hot aggregate raw materials into the hot aggregate scale in stages.

[0017] Step 2: The RAP material elevator transports the RAP material raw material to the RAP material buffer silo. The RAP material raw material is fed into the hot aggregate scale in batches through the RAP material scale, dividing the RAP material into RAP material B1, RAP material B2, RAP material B3, RAP material B4... RAP material B (nm), where m is automatically adjustable: adjusted according to the amount of RAP material added and heating requirements, with a minimum of 1 and a maximum of n-1.

[0018] Step 3: The graded hot aggregates A1, A2, A3, A4, A5...An, and the graded RAP materials B1, B2, B3, B4...B (nm) are stacked together in the hot aggregate scale. The RAP materials and the hot aggregates in the hot aggregate bins are simultaneously added to the hot aggregate scale. During the stacking and metering process of the hot aggregates and RAP materials, the hot aggregate scale and the RAP material scale alternately accumulate the data to achieve efficient, accurate, and controllable metering of the hot aggregates and RAP materials. After heating, the aggregate is added in stages and at different times according to the production mix ratio and the actual number of aggregate grades through the hot aggregate bin. The maximum number of RAP material additions is one grade less than the number of hot aggregate grades. This setting ensures that the RAP is completely covered by the hot aggregate. After the first grade of hot aggregate is added, the RAP material is added layer by layer on top of the hot aggregate. After both aggregates are added in proportion and weight, the initial layered and uniform mixing is achieved. The mixing time of the mixture is fully utilized to achieve heat conduction and heat radiation from the hot aggregate to the RAP material. Then, it is simultaneously added to the mixing pot, where it is mixed and heat exchanged again, effectively achieving the asphalt mixture gradation and temperature qualification.

[0019] Step 4: After weighing the mineral powder in the powder tank with a powder scale, put it into the mixing pot; after weighing the asphalt in the asphalt storage tank with an asphalt scale, put it into the mixing pot.

[0020] Step 5: Mix all the ingredients in a mixing pot. The wet mixing time should be 5-10 seconds longer than the normal mixing time.

[0021] As a further aspect of the present invention: hot aggregate A1 is laid on the bottom layer of a hot aggregate scale, and the hot aggregate A1 is weighed by the hot aggregate scale as GC1. At this time, the weight of hot aggregate A1 is GA1=GC1. According to the ratio between aggregate and RAP material, RAP material B1 is weighed by the RAP material scale as GB1. RAP material B1 is then laid on top of the hot aggregate A1 layer. At this time, the weight displayed on the hot aggregate scale is GA1+GB1, that is, GC1+GB1. Then, hot aggregate A2 is laid on top of the RAP material B1 layer. The total weight of hot aggregate A1, RAP material B1 and hot aggregate A2 is weighed by the hot aggregate scale as GC2. The weight of hot aggregate A2 is GA2=GC2-( GC1+GB1), when RAP material B2 passes through the RAP material scale, the weight is GB2. Then RAP material B2 is laid on top of hot aggregate A2. At this time, the weight displayed on the hot aggregate scale is GC2+GB2. Then hot aggregate A3 is laid on top of RAP material B2. The total weight of hot aggregate A1, RAP material B1, hot aggregate A2, RAP material B2 and hot aggregate A3 is weighed by the hot aggregate scale and is GC3. The weight of hot aggregate A3 is GA3=GC3-(GC2+GB2)...... Then hot aggregate An is laid on top of RAP material B(n-1). The weight of hot aggregate An is GAn=GCn-[GC(n-1)+GB(n-1)].

[0022] The beneficial effects of this invention are:

[0023] 1. This invention involves stacking graded hot aggregate and fractionated RAP material in a hot aggregate weigher. During the stacking and metering process, the hot aggregate weigher and RAP material weigher alternately accumulate the material to achieve layering and coating, ensuring accurate and controllable metering of both materials. This overcomes the shortcomings of inaccurate metering in previous external addition systems. The invention enables the hot aggregate to be added in grades and at different times according to the actual number of grades, and the RAP material to be added in fractions and at different times. This setup ensures that the RAP material is completely coated with the hot aggregate, and the two materials are stacked and fused together, achieving premixing and preheating, effectively guaranteeing high-quality production of asphalt mixtures.

[0024] 2. This invention uses road RAP material to replace part of the original aggregate, making full use of the residual asphalt in the RAP material to achieve the recycling of RAP material, saving costs, reducing environmental pollution, and meeting the urgent requirements of resource-saving and environmentally friendly industry construction. It has significant economic and social benefits. The two aggregates are added in proportion and weight to achieve preliminary layered uniform mixing. The mixing time of the mixture is fully utilized to achieve heat conduction and heat radiation of the hot aggregate to the RAP material. Then, they are simultaneously added to the mixing pot. By extending the dry mixing and wet mixing time, uniform mixing and heat exchange are carried out again in the mixing pot, effectively achieving the asphalt mixture gradation and temperature qualification. Attached Figure Description

[0025] The invention will now be further described with reference to the accompanying drawings.

[0026] Figure 1 This is a block diagram of a production system for cold feeding and stacking of RAP material according to the present invention.

[0027] In the diagram: 1. Hot aggregate elevator; 2. Vibrating screen; 3. Hot aggregate bin; 4. Hot aggregate scale; 5. Asphalt storage tank; 6. Asphalt scale; 7. RAP material elevator; 8. RAP material buffer bin; 9. RAP material scale; 10. Powder tank; 11. Powder scale; 12. Mixing pot. Detailed Implementation

[0028] 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.

[0029] like Figure 1 As shown, a production system for cold-feeding and stacking RAP material includes a hot material silo 3, a RAP material buffer silo 8, and a hot aggregate scale 4. A vibrating screen 2 is installed above the hot material silo 3, and a hot aggregate elevator 1 is installed on one side of the vibrating screen 2. A RAP material elevator 7 is installed on one side of the RAP material buffer silo 8, and a RAP material scale 9 is installed below the RAP material buffer silo 8. The conveying end of the hot material silo 3 is correspondingly set to the feeding end of the hot aggregate scale 4, and the conveying end of the RAP material scale 9 is correspondingly set to the feeding end of the hot aggregate scale 4. A mixing pot 12 is installed below the hot aggregate scale 4, and the conveying end of the hot aggregate scale 4 is correspondingly set to the feeding end of the mixing pot 12.

[0030] In some specific implementations, the conveying end of the hot aggregate elevator 1 is set to correspond to the feeding end of the vibrating screen 2, and the conveying end of the vibrating screen 2 is set to correspond to the feeding end of the hot aggregate bin 3.

[0031] In some specific implementations, the conveying end of the RAP material elevator 7 is set to correspond to the feeding end of the RAP material buffer bin 8, and the conveying end of the RAP material buffer bin 8 is set to correspond to the feeding end of the RAP material scale 9.

[0032] A production system for cold-feeding and stacking RAP material also includes a powder tank 10 and an asphalt storage tank 5. A powder scale 11 is installed below the powder tank 10, and an asphalt scale 6 is installed below the asphalt storage tank 5. The conveying end of the powder tank 10 is corresponding to the feeding end of the powder scale 11, the conveying end of the powder scale 11 is corresponding to the feeding end of the mixing pot 12, the conveying end of the asphalt storage tank 5 is corresponding to the feeding end of the asphalt scale 6, and the conveying end of the asphalt scale 6 is corresponding to the feeding end of the mixing pot 12.

[0033] A method for cold-feeding and stacking RAP material includes the following steps:

[0034] Step 1: The heated hot aggregate raw materials are conveyed to the vibrating screen 2 through the hot aggregate elevator 1. The heating temperature of the raw aggregate is 190℃-200℃. The vibrating screen 2 screens the hot aggregate raw materials. The screened hot aggregate raw materials enter the hot aggregate bin 3 for storage. The hot aggregate raw materials are added to the hot aggregate scale 4 in batches to divide the hot aggregate raw materials into hot aggregate A1, hot aggregate A2, hot aggregate A3, hot aggregate A4, hot aggregate A5... hot aggregate An.

[0035] Step 2: The RAP material elevator 7 conveys the RAP material raw material to the RAP material buffer silo 8. The RAP material raw material is divided by the RAP material scale 9 and put into the hot aggregate scale 4, dividing the RAP material into RAP material B1, RAP material B2, RAP material B3, RAP material B4... RAP material B (nm).

[0036] Step 3: The graded hot aggregates A1, A2, A3, A4, A5...An, and the graded RAP materials B1, B2, B3, B4...B (nm) are stacked together in the hot aggregate scale 4. The RAP materials and the hot aggregates in the hot aggregate bin are simultaneously stacked and fed into the hot aggregate scale 4. During the stacking and metering process of the hot aggregates and RAP materials, the hot aggregate scale and the RAP material scale alternately accumulate to achieve efficient and precise metering of the hot aggregates and RAP materials. After heating, the hot aggregates are fed into the hot aggregate bin according to production schedules. The aggregate is added in stages and at different times according to the actual number of aggregate grades. The maximum number of RAP additions is one grade less than the number of hot aggregate grades. This setting ensures that the RAP is completely coated in the hot aggregate. After the first grade of hot aggregate is added, the RAP is added layer by layer on top of the hot aggregate. After both aggregates are added in proportion and by weight, preliminary layered and uniform mixing is achieved. The mixing time of the mixture is fully utilized to allow the hot aggregate to conduct heat and radiate heat to the RAP. Then, it is simultaneously added to the mixing pot 12, where it is mixed and heat exchanged again. This effectively achieves the asphalt mixture gradation and temperature compliance. Specifically, hot aggregate A1 is laid in a layer on the bottom surface of the hot aggregate scale 4. Hot aggregate A1 is weighed using hot aggregate scale 4 and recorded as GC1. At this point, the weight of hot aggregate A1 is GA1 = GC1. Based on the ratio between the hot aggregate and RAP material, RAP material B1 is weighed using RAP material scale 9 and recorded as GB1. RAP material B1 is then laid on top of the hot aggregate A1 layer. At this point, the weight displayed on hot aggregate scale 4 is GA1 + GB1, i.e., GC1 + GB1. Then, hot aggregate A2 is laid on top of the RAP material B1 layer. The total weight of hot aggregate A1, RAP material B1, and hot aggregate A2 is weighed using hot aggregate scale 4 and recorded as GC2. The weight of hot aggregate A2 is GA2 = GC2 - (GC1 + GB1). 2. When the RAP material is weighed by the RAP material scale 9, the weight is GB2. Then, RAP material B2 is laid on top of the hot aggregate A2 layer. At this time, the weight displayed on the hot aggregate scale 4 is GC2+GB2. Then, hot aggregate A3 is laid on top of RAP material B2. The total weight of hot aggregate A1, RAP material B1, hot aggregate A2, RAP material B2 and hot aggregate A3 is weighed by the hot aggregate scale 4 and the weight is GC3. The weight of hot aggregate A3 is GA3=GC3-(GC2+GB2)...... Then, hot aggregate An is laid on top of the RAP material B(n-1) layer. The weight of hot aggregate An is GAn=GCn-[GC(n-1)+GB(n-1)].

[0037] Step 4: After the mineral powder in powder tank 10 is weighed by powder scale 11, it is put into mixing pot 12. After the asphalt in asphalt storage tank 5 is weighed by asphalt scale 6, it is put into mixing pot 12.

[0038] Step 5: Mix all the ingredients in mixing pot 12. The wet mixing time of the mixture should be 5-10 seconds longer than the normal mixing time.

[0039] To facilitate understanding of the embodiments of this solution by those skilled in the art, the working principle of this solution will now be briefly explained in conjunction with specific application scenarios:

[0040] This invention uses road RAP material to replace part of the original aggregate, makes full use of the residual asphalt in the RAP material, realizes the recycling of RAP material, saves costs, reduces environmental pollution, meets the urgent requirements of resource-saving and environmentally friendly industry construction, and has significant economic and social benefits.

[0041] The hot aggregate and RAP material after separation are stacked together in the hot aggregate scale 4. During the stacking process, the hot aggregate scale 4 and the RAP material scale 9 can be used to realize the segmented and timed metering of hot aggregate and RAP material, accurately realize the metering control and proportion control of hot aggregate and RAP material, make up for the shortcomings of the previous external addition system metering inaccurate, realize the segmented and timed metering of RAP material and hot aggregate, and the two materials are stacked and accumulated and fused. Through premixing and preheating, the mixing quality of asphalt mixture is effectively guaranteed.

[0042] This invention delivers RAP material in batches and at different times, and hot aggregate in batches and at different times, forming a cumulative and mutually covering effect. This extends the heat exchange time between RAP material and hot aggregate, achieving a uniform distribution of RAP material and new aggregate. At the same time, by extending the dry mixing and wet mixing time, it ensures high-quality production of asphalt mixtures.

[0043] The foregoing has described several embodiments of the present invention in detail, but these embodiments are not limited thereto and should not be considered as limiting the scope of the invention. All equivalent variations and improvements made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A production method for cold-feeding and stacking RAP material, characterized in that, include: A hot aggregate bin (3) is provided above the hot aggregate bin (3), and a vibrating screen (2) is provided on one side of the vibrating screen (2); RAP material buffer silo (8), RAP material elevator (7) is installed on one side of RAP material buffer silo (8), and RAP material scale (9) is installed below RAP material buffer silo (8). The conveying end of the hot aggregate scale (4) and the feeding end of the hot aggregate bin (3) are respectively set to correspond to the feeding end of the hot aggregate scale (4). The conveying end of the RAP scale (9) is respectively set to correspond to the feeding end of the hot aggregate scale (4). A mixing pot (12) is set below the hot aggregate scale (4). The conveying end of the hot aggregate scale (4) is respectively set to correspond to the feeding end of the mixing pot (12). It also includes a powder tank (10) and an asphalt storage tank (5). A powder scale (11) is installed below the powder tank (10), and an asphalt scale (6) is installed below the asphalt storage tank (5). The production method includes the following steps: S1: The heated hot aggregate raw materials are conveyed to the vibrating screen (2) through the hot aggregate elevator (1). The heating temperature of the raw aggregate is 200℃. The vibrating screen (2) screens the hot aggregate raw materials. The screened hot aggregate raw materials are stored in the hot aggregate bin (3) in batches. The hot aggregate in the hot aggregate bin (3) is accumulated and measured in batches and time by the hot aggregate scale (4). The hot aggregate raw materials are divided into hot aggregate A1, hot aggregate A2, hot aggregate A3, hot aggregate A4, hot aggregate A5... hot aggregate An; S2: The RAP material elevator (7) transports the cold RAP material to the RAP material buffer silo (8). The RAP material raw material is fed into the hot aggregate scale (4) in batches and timed by the RAP material scale (9). The RAP material is divided into RAP material B1, RAP material B2, RAP material B3, RAP material B4... RAP material B (nm) times, where m is automatically adjustable: it is adjusted according to the amount of RAP material added and the heating requirements. The minimum is 1 and the maximum is n-1. S3: The graded hot aggregates A1, A2, A3, A4, A5...An, and the graded RAP materials B1, B2, B3, B4...B (nm) are stacked in the hot aggregate scale (4). The RAP materials and the hot aggregates in the hot aggregate bin (3) are simultaneously stacked and fed into the hot aggregate scale (4). During the stacking and metering process of hot aggregates and RAP materials, the hot aggregate scale (4) and the RAP material scale (9) can be alternately accumulated to achieve the stacking and covering of hot aggregates and RAP materials, and to efficiently achieve accurate and controllable metering of hot aggregates and RAP materials. After heating, the aggregate is fed into the hot aggregate bin (3) according to the production mix ratio and the actual number of aggregate grades. The maximum number of RAP material feedings is one grade less than the number of hot aggregate grades. This setting ensures that the RAP material is completely covered in the hot aggregate. After the first grade of hot aggregate is fed, the RAP material is added layer by layer on top of the hot aggregate. The two aggregates are fed in proportion and weight to achieve initial layered uniform mixing. The mixing time of the mixture is fully utilized to achieve heat conduction and heat radiation from the hot aggregate to the RAP material. Then, it is fed into the mixing pot (12) at the same time. In the mixing pot (12), it is mixed uniformly and heat exchanged again, effectively achieving the grade and temperature qualification of the asphalt mixture. S4: The mineral powder in the powder tank (10) is weighed by the powder scale (11) and then put into the mixing pot (12); the asphalt in the asphalt storage tank (5) is weighed by the asphalt scale (6) and then put into the mixing pot (12). S5: Mix all the raw materials in the mixing pot (12), and the wet mixing time of the mixture is 10 seconds longer than the normal mixing time.

2. The production method of cold-feeding and stacking RAP material according to claim 1, characterized in that, In S3, hot aggregate A1 is laid on the bottom layer of the hot aggregate scale (4). The hot aggregate A1 is weighed by the hot aggregate scale (4) as GC1. At this time, the weight of hot aggregate A1 is GA1=GC1. According to the ratio between aggregate and RAP material, RAP material B1 is weighed by the RAP material scale (9) as GB1. RAP material B1 is laid on top of the hot aggregate A1 layer. At this time, the weight displayed on the hot aggregate scale (4) is GA1+GB1, that is, GC1+GB1. Then, hot aggregate A2 is laid on top of the RAP material B1 layer. The total weight of hot aggregate A1, RAP material B1 and hot aggregate A2 is weighed by the hot aggregate scale (4) as GC2. The weight of hot aggregate A2 is GA2=GC2-( When RAP material B2 passes through the RAP material scale (9), the weight is measured as GB2. Then RAP material B2 is laid on top of the hot aggregate A2 layer. At this time, the weight displayed on the hot aggregate scale (4) is GC2+GB2. Then hot aggregate A3 is laid on top of RAP material B2. The total weight of hot aggregate A1, RAP material B1, hot aggregate A2, RAP material B2 and hot aggregate A3 is measured and weighed by the hot aggregate scale (4) as GC3. The weight of hot aggregate A3 is GA3=GC3-(GC2+GB2)......Then hot aggregate An is laid on top of the RAP material B(n-1) layer. The weight of hot aggregate An is GAn=GCn-[GC(n-1)+GB(n-1)].

Images