asphalt plant

Abstract

The present application provides an asphalt plant capable of producing an asphalt mixture while uniformly foaming molten asphalt. A water nozzle (20) that sprays water to molten asphalt is provided at a portion of an asphalt supply pipe (19) on the downstream side of a supply pump (18), a stirring mixing section (21) that mixes water and molten asphalt is provided at a portion on the downstream side of the water nozzle, a cylinder (22) having a larger diameter than the asphalt supply pipe is provided, a funnel-shaped connection portion (25) connects the cylinder with an inlet portion (23) and an outlet portion (24), the inlet and outlet portions are connected to the cylinder in a manner in which the respective central axes are offset, on the other hand, a column (27) penetrates the cylinder in a direction orthogonal to the downward direction at an intermediate position in the downward direction of the cylinder, and the molten asphalt to which water is added and which is stirred and mixed by being subjected to turbulent flow in the cylinder is supplied to a mixer (10).

Description

Technical Field

[0001] This invention relates to an asphalt plant for manufacturing asphalt mixtures as road paving materials, and to an asphalt plant for manufacturing asphalt mixtures using foamed molten asphalt. Background Technology

[0002] In the past, when manufacturing asphalt mixtures, the following situation existed: a predetermined amount of water or water vapor was added to molten asphalt, which is the raw material of the asphalt mixture, to make it foam (foamed), and the foamed molten asphalt (hereinafter referred to as "foamed asphalt") was mixed with aggregates, stone powder, etc. using a mixer to manufacture asphalt mixtures.

[0003] As a device for foaming molten asphalt, the applicant has also filed an application for an asphalt plant as shown in Patent Document 1 (Japanese Patent Application Publication No. 2020-94367). In this application, a switching valve is provided on the downstream side of the supply pump, which is provided with an asphalt supply pipe that supplies molten asphalt metered by an asphalt metering tank to the mixer. The valve allows selection between a supply path that feeds molten asphalt into the mixer and a circulation path that feeds molten asphalt back to the supply pump. A water nozzle that sprays water supplied by a water supply source onto the molten asphalt is connected to the middle of the circulation path. The molten asphalt is foamed by spraying water from the water nozzle while circulating within the circulation path, and then supplied to the mixer.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2020-94367 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] However, while the aforementioned conventional apparatus achieves relatively uniform foaming by adding water to the molten asphalt and circulating it within a circulation path, the additional circulation path added to the asphalt supply piping solely for foaming results in a slightly larger structure, requiring corresponding space and cost for installation. Furthermore, if the switching valve connected to the asphalt supply piping malfunctions, replacing the malfunctioning valve is extremely troublesome, as it could potentially affect the production of the asphalt mixture.

[0009] In view of the above points, the present invention aims to provide an asphalt plant that can produce asphalt mixtures by foaming molten asphalt in a substantially uniform manner with a simple structure.

[0010] Solution for solving the problem

[0011] To solve the above problems, in the asphalt plant according to technical solution 1 of the present invention, a vibrating screen, aggregate storage bin, aggregate metering tank, and mixer are assembled in a layered manner on an elevated platform. The plant includes an asphalt supply pipe and a supply pump for supplying molten asphalt metered by the asphalt metering tank to the mixer. The plant is characterized in that a water nozzle for injecting water into the molten asphalt is provided on the downstream side of the asphalt supply pipe from the supply pump. A mixing section for mixing water and molten asphalt is provided on the downstream side of the water nozzle on the asphalt supply pipe. This mixing section has a cylindrical body with a larger diameter than the asphalt supply pipe. An inlet and an outlet are connected to both ends of the cylindrical body by a funnel-shaped connecting part. The inlet and outlet are connected to the cylindrical body with their respective central axes offset. Furthermore, a column is made to penetrate the cylindrical body at the middle position in the downward flow direction in a direction orthogonal to the downward flow direction. After the molten asphalt containing water flowing down the cylindrical body is stirred and mixed by creating turbulence, it is supplied to the mixer.

[0012] Furthermore, in the asphalt plant according to technical solution 2, the inner wall surface of the connection between the cylinder and the inlet and outlet is provided with an obstacle that hinders the flow of water and molten asphalt flowing down into the cylinder.

[0013] The effects of the invention

[0014] According to technical solution 1 of the present invention, in an asphalt plant, a water nozzle for injecting water into molten asphalt is provided on the downstream side of the asphalt supply pipe, the supply pump being clamped to the asphalt supply pipe supplying metered molten asphalt to a mixer. A mixing section for mixing water and molten asphalt is provided on the downstream side of the asphalt supply pipe, the mixing section having a cylindrical body with a larger diameter than the asphalt supply pipe. An inlet and an outlet are connected to both ends of the cylindrical body by a funnel-shaped connecting part. The inlet... The inlet and outlet are connected to the cylinder in such a way that their respective central axes are offset. Meanwhile, a column is inserted through the cylinder at a position midway down the flow direction, perpendicular to the flow direction. After stirring and mixing the molten asphalt containing water flowing down the cylinder, it is supplied to the mixer. Therefore, the flow of the molten asphalt containing water from the inlet to the outlet of the cylinder is turbulent, allowing water to be evenly dispersed in the molten asphalt. This ensures that the molten asphalt, which has been roughly uniformly foamed, is supplied to the mixer when discharged. Furthermore, the simplified structure, where mechanical components such as path switching valves are not embedded in the asphalt supply piping, reduces costs and prevents adverse situations such as the inability to supply molten asphalt. Additionally, the simplified structure allows for a compact and centralized overall installation, minimizing installation space and facilitating installation in existing plants.

[0015] Furthermore, according to the asphalt plant described in technical solution 2, an obstacle is provided on the inner wall of the connection between the cylinder and the inlet and outlet sections to prevent the flow of water and molten asphalt flowing down into the cylinder. Therefore, while keeping the molten asphalt with added water flowing down from the inlet to the outlet section of the cylinder in the cylinder, turbulence is generated, thereby enabling the water to be dispersed more effectively and uniformly. As a result, approximately uniformly foamed molten asphalt can be supplied to the mixer. Attached Figure Description

[0016] Figure 1 This is a schematic diagram illustrating the asphalt plant of the present invention.

[0017] Figure 2 This is an explanatory diagram of the main parts of the asphalt metering and supply device of the present invention.

[0018] Figure 3 This is a magnified front view of a section omitting the stirring and mixing part.

[0019] Figure 4 This is an enlarged side view of a portion of the mixing section, omitting the stirring and mixing part.

[0020] Figure 5 It was omitted. Figure 3 A partial AA section view.

[0021] Figure 6 It was omitted. Figure 4 A partial BB cross-sectional view.

[0022] Figure 7 This indicates an alternative implementation. Figure 2 The image.

[0023] Figure 8 This indicates an alternative implementation method. Figure 2 The image.

[0024] Explanation of reference numerals in the attached figures

[0025] 10. Mixer; 11. Asphalt metering and supply device; 17. Asphalt metering tank; 18. Supply pump; 19. Asphalt supply piping; 20. Water nozzle; 21. Mixing and stirring section; 22. Cylinder; 23. Inlet section; 24. Outlet section; 25. Connecting section; 27. Column. Detailed Implementation

[0026] In the asphalt plant of the present invention, in a conventionally constructed plant, a water nozzle that sprays water to add to molten asphalt is connected to a portion of the asphalt supply pipe located downstream of a supply pump, such as a gear pump. The supply pump is clamped in an asphalt supply pipe with a circular cross-section that supplies molten asphalt from an asphalt metering tank to a mixer. A mixing section for mixing water and molten asphalt is provided in a portion of the asphalt supply pipe located downstream of the water nozzle.

[0027] The mixing section has a cylindrical body with a diameter larger than that of the asphalt supply pipe with a circular cross-section. The two ends of the cylindrical body are connected by funnel-shaped connecting parts. Furthermore, the central axes of the cylindrical body, the inlet, and the outlet are arranged in parallel on the same plane.

[0028] Furthermore, the inlet and outlet are slightly offset from each other with their respective central axes not aligned in a straight line and connected to the cylinder, creating a meandering flow path for the water-added molten asphalt flowing down from the inlet to the outlet (in this invention, "downward flow" means flowing to the downstream side, not downwards). Additionally, a cylindrical column, for example with a circular cross-section, is inserted at the middle position of the cylinder in the downward flow direction, perpendicular to the downward flow direction. This causes the water-added molten asphalt inside the cylinder to collide with the column, thereby creating turbulence in the water-added molten asphalt flowing down in the mixing section and mixing it. This allows the molten asphalt to be supplied to the mixer in a uniformly dispersed water state.

[0029] Furthermore, when manufacturing an asphalt mixture using foamed asphalt as raw material in the aforementioned structural asphalt plant, the required amount of asphalt is calculated using the plant operation panel based on the mixing ratio of the asphalt mixture to be manufactured, and one batch of molten asphalt is measured using the asphalt metering tank.

[0030] On the other hand, aggregates of various particle sizes are discharged from the aggregate storage bin to the aggregate metering tank based on the stated proportions, and the accumulated aggregates and other metered materials such as stone powder are fed into the mixer for pre-mixing (dry mixing).

[0031] After premixing, molten asphalt is discharged from the asphalt metering tank, and a supply pump is driven to spray water from the water nozzle onto the molten asphalt flowing down into the mixing section in the asphalt supply pipe. The water volume is added in a predetermined proportion, for example, about 1% to 3% by weight, preferably about 2% by weight, of the metered molten asphalt volume.

[0032] The water added to the molten asphalt vaporizes and flows down into the mixing section along with the molten asphalt. As it flows down from the inlet section of the mixing section, which has a flow path formed in a meandering manner, to the outlet section, it collides with the column that runs through the cylinder. This causes turbulence and agitation in the flow. The added water is evenly dispersed into the molten asphalt and discharged from the outlet section to the asphalt supply pipe.

[0033] By mixing and stirring in the mixing section, the vaporized water is evenly dispersed into the molten asphalt. Foamed asphalt with approximately uniform properties can be fed into the mixer that has finished preparing for mixing, and mixed with materials such as aggregates in the mixer to produce an asphalt mixture using foamed asphalt as raw material.

[0034] Furthermore, it is preferable to provide a barrier at the connection between the inlet and the cylinder to prevent the molten asphalt containing water from diffusing into the cylinder along the inner wall of the connection, which is wider than the inlet. On the other hand, it is preferable to provide a barrier at the connection between the cylinder and the outlet to prevent the molten asphalt containing water from flowing down the inner wall of the connection, which is narrower than the cylinder, into the outlet.

[0035] In this way, a portion of the molten asphalt with added water introduced by the inlet does not collide with the column due to the obstacle on the inlet side, and flows down along the inner wall of one side of the cylinder towards the outlet side. Due to the obstacle on the outlet side, it does not exit directly from the outlet, but temporarily returns into the cylinder and flows down from the inner wall of the other side of the cylinder towards the inlet.

[0036] On the other hand, a portion of the molten asphalt with added water introduced from the inlet diffuses into the cylinder and collides with the column. At the same time, it flows down from the inner wall side of the cylinder towards the outlet, colliding with the (returning) molten asphalt with added water flowing down towards the inlet. This generates strong turbulence in the cylinder and mixes the mixture. Then it is discharged from the outlet. Thus, molten asphalt can be supplied to the mixer in a more efficient and uniform state with water.

[0037] In this way, water added by spraying is evenly dispersed in the molten asphalt added into the mixer. Although it is a simple equipment structure with the mixing unit sandwiched in the asphalt supply pipe, it is possible to generate foamed asphalt with a generally uniform shape. By using this foamed asphalt as raw material, it is expected that materials such as aggregates and stone powder will be well mixed in the mixer. It is anticipated that even if the manufacturing temperature is lowered than before, the desired asphalt mixture can be produced.

[0038] In addition, the molten asphalt with added water is supplied to the mixer only through the mixing section. Therefore, the time required from metering to discharge to the mixer is comparable to that required to discharge ordinary molten asphalt without added water. Even when foamed asphalt is used to manufacture asphalt mixtures, the hourly manufacturing efficiency is not reduced.

[0039]

Example

[0040] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0041] Figure 1 Reference numeral 1 in the attached diagram refers to an asphalt plant that manufactures asphalt mixtures as road paving materials. It is primarily composed of a plant main body 2, asphalt tanks 3 for insulated storage of molten asphalt, and control panels 4 for operating and controlling various plant devices. The plant main body 2 is erected on a multi-story elevated platform 5. Bucket elevators 6 are arranged side-by-side on the side of this elevated platform 5 to lift newly dried aggregates (not shown) to the top of the platform 5.

[0042] The elevated platform 5 is arranged in a layered manner with the following components: a vibrating screen 7, which screens the heated aggregate discharged from the bucket elevator 6 according to particle size; an aggregate storage bin 8, which stores the aggregate screened by the vibrating screen 7 according to particle size; an aggregate metering trough 9, which accumulates and measures aggregates of various particle sizes discharged from the aggregate storage bin 8; a mixer 10, which mixes aggregates and various materials such as molten asphalt; and an asphalt metering and supplying device 11, which measures molten asphalt and supplies it to the mixer 10.

[0043] The asphalt metering and supply device 11 is connected to an asphalt supply pipe 12 that supplies molten asphalt from the asphalt tank 3 and a water supply pipe 14 that supplies water from the water storage tank 13, which serves as a water supply source. Supply pumps 15 and 16 are respectively installed in the middle of the asphalt supply pipe 12 and the water supply pipe 14.

[0044] Figure 2 This is a schematic diagram of the asphalt metering and supply device 11. The asphalt metering and supply device 11 includes: an asphalt metering tank 17, which meters molten asphalt supplied via the asphalt supply pipe 12; and an asphalt supply pipe 19, which is equipped with a supply pump 18, such as a gear pump, for supplying the metered molten asphalt to the mixer 10.

[0045] Additionally, a water nozzle 20 is connected midway through the asphalt supply pipe 19 to inject water supplied from the water supply pipe 14 into the molten asphalt, and a mixing section 21 for mixing water and molten asphalt is sandwiched in the portion of the asphalt supply pipe 19 downstream of the water nozzle 20.

[0046] like Figures 3-6As shown, the mixing unit 21 includes a cylindrical body 22 with a diameter approximately three times larger than that of the asphalt supply pipe 19. A funnel-shaped connecting portion 25 connects a circular inlet portion 23 and an outlet portion 24 to both ends of the cylindrical body 22. The connecting portion 25 on the inlet portion 23 side expands its inner diameter toward the cylindrical body 22, while the connecting portion 25 on the outlet portion 24 side contracts its inner diameter toward the outlet portion 24, which has the same inner diameter as the asphalt supply pipe 19.

[0047] Furthermore, the central axes of the cylinder 22, the inlet 23, and the outlet 24 are each arranged on the same plane and are parallel to each other. The central axis of the inlet 23 and the central axis of the outlet 24 are located on opposite sides of each other, separated by the central axis of the cylinder 22. When the inlet 23 is extended in the direction of the central axis α, the inlet 23 and the outlet 24 are connected to the cylinder 22 at different heights via the connecting part 25, ensuring that the shape of the outlet 24 does not overlap with the shape of the extended inlet 23. The molten asphalt containing water, introduced into the mixing section 21, flows down in a meandering pattern.

[0048] In addition, the connecting part 25 is provided with: a barrier 26a, which prevents the molten asphalt with added water from diffusing from the inlet part 23 into the cylinder 22; and a barrier 26b, which prevents the molten asphalt with added water from flowing down from the cylinder 22 along the inner wall of the connecting part 25 toward the outlet part 24.

[0049] Furthermore, a circularly shaped column 27 is provided at the midpoint of the flow direction of the cylinder 22, penetrating near the central axis of the cylinder 22 in a direction orthogonal to the plane passing through the central axes of the cylinder 22, the inlet 23, and the outlet 24. Additionally, the gap C between the inner wall surface of the cylinder 22 and the outer wall surface of the column 27 is ensured to be equal to the inner diameter of the asphalt supply pipe 19.

[0050] like Figure 6 As shown, the aforementioned obstacle 26a protrudes from the inner wall surface of the connecting portion 25 on the inlet side toward the space between the inlet portion 23 and the pillar 27. Additionally, the aforementioned obstacle 26b protrudes from the inner wall surface of the connecting portion 25 on the outlet side toward the space between the outlet portion 24 and the pillar 27.

[0051] If water is sprayed from the water nozzle 20 into the molten asphalt (at approximately 160°C) flowing into the mixer 10 through the asphalt supply pipe 19, the water vaporizes and is simultaneously introduced into the mixing section 21, where it is mixed with the molten asphalt, thereby foaming approximately uniformly and being discharged through the outlet section 24.

[0052] In addition, the asphalt metering tank 17 consists of a metering tank body 29 suspended and supported by a load sensor 28 and a buffer tank 30 that temporarily receives the molten asphalt discharged from the metering tank body 29.

[0053] An inlet 31 is provided at the upper part of the metering tank body 29 for the discharge end of the asphalt supply pipe 12 to pass through, and an outlet 32 ​​is provided at the lower end for discharging the metered molten asphalt. Furthermore, it has an opening and closing mechanism composed of a cylinder 33, a piston rod 34, and a plug 35. The plug 35 can be opened and closed by the extension and retraction of the piston rod 34 causing the plug 35 to move forward and backward in the vertical direction.

[0054] Additionally, reference numeral 36 in the figure is a discharge door for discharging aggregates of various sizes stored in each compartment of the aggregate storage bin 8; reference numeral 37 is a load sensor that suspends and supports the aggregate metering trough 9 for metering; reference numeral 38 is a discharge door for discharging aggregates that have been accumulated and metered by the aggregate metering trough 9; reference numeral 39 is an asphalt nozzle for injecting molten asphalt supplied by the asphalt supply pipe 19 into the mixer 10; and reference numeral 40 is the mixing blade of the mixer 10.

[0055] The control panel 4 is the control unit for controlling the asphalt plant 1. The control panel 4 is electrically connected to the aforementioned parts of the asphalt plant 1. The control panel 4 is, for example, composed of a computer, and controls the operation of the various parts of the asphalt plant 1 according to a predetermined program. When manufacturing an asphalt mixture using foamed asphalt as raw material in the asphalt plant 1 with the above-described structure, the type and quantity of the asphalt mixture to be manufactured are first input into the control panel 4.

[0056] According to the input ratio of the asphalt mixture to be manufactured, the operating panel 4 discharges aggregate from each compartment of the aggregate storage bin 8 to the aggregate metering tank 9 and begins to accumulate and measure. On the other hand, a batch of molten asphalt is measured at the asphalt metering tank 17.

[0057] Once the cumulative metering of aggregates is complete, they are fed into mixer 10 along with other metered materials such as stone powder for pre-mixing (dry mixing). Additionally, in the asphalt metering tank 17, where the metering of molten asphalt has been completed, the outlet 32 ​​of the metering tank body 29 is opened to discharge the metered molten asphalt, and the supply pump 18 installed in the asphalt supply pipe 19 is activated.

[0058] A predetermined amount of water, corresponding to a pre-set water addition ratio, is sprayed from the water nozzle 20 onto the molten asphalt flowing down the asphalt supply pipe 19 into the mixer 10. Furthermore, according to the results of experiments conducted by the inventors, if the water addition ratio to the molten asphalt is less than 1% by weight, the amount of water added is too small, and a suitable foamed asphalt cannot be obtained. On the other hand, it was confirmed that adding 2% or more of water yields good foamed asphalt. However, even when comparing asphalt mixtures using foamed asphalt with more than 3% by weight of added water with asphalt mixtures using foamed asphalt with approximately 2% by weight of added water, no difference in properties can be confirmed. Based on the above, it is preferable to set the water addition ratio to approximately 2% by weight (e.g., 1.5% to 2.5% by weight).

[0059] Molten asphalt, with a predetermined amount of water added from the water nozzle 20, flows down the asphalt supply pipe 19 and is introduced into the inlet 23 of the mixing section 21. (Refer to...) Figure 6 The cross-sectional view illustrates the flow within the mixing section 21. A portion of the molten asphalt with added water introduced by the inlet section 23 does not diffuse into the cylinder 22 due to the barrier 26a provided at the connecting section 25 on the inlet side, but instead flows along... Figure 6 The water flows down the inner wall of the lower side of the cylinder 22 toward the outlet 24, and temporarily returns toward the inner wall of the upper side of the cylinder 22 due to the obstacle 26b of the connecting part 25 provided to the outlet 24.

[0060] On the other hand, a portion of the molten asphalt mixed with water introduced by the inlet 23 diffuses into the cylinder 22 and collides with the column 27, while also... Figure 6 The water flows down the inner wall of the upper side of the cylinder 22 and collides with the molten asphalt containing water that returns from the outlet 24 side along the inner wall of the upper side of the cylinder 22 to the inlet 23 side, thereby generating strong turbulence in the cylinder 22 and mixing it to make the water evenly dispersed into the molten asphalt.

[0061] In the mixing section 21, the water in the molten asphalt is vaporized and mixed with the molten asphalt. While foaming in a roughly uniform manner, the water is discharged from the outlet section 24 into the downstream asphalt supply pipe 19 and fed into the mixer 10, which has finished the pre-mixing process, from the downstream asphalt nozzle 39. The mixture is then mixed with the aggregate and other materials in the mixer 10 to produce the desired asphalt mixture.

[0062] Figure 7 This diagram illustrates another embodiment where the mixing section 21 is rotated 90° around the central axis of the cylinder 22 and connected to the asphalt supply pipe 19 in a horizontal manner with the inlet section 23 and the outlet section 24. Additionally, Figure 8This is a diagram showing another embodiment in which the mixing section 21 is connected to the asphalt supply pipe 19 with the outlet section 24 located below the inlet section 23. Even so Figure 7 , Figure 8 As shown, the mixing section 21 is connected to the asphalt supply pipe 19. The flow path of the molten asphalt with added water meanders in the mixing section 21 in the same way as described above, and collides with the column 27 in the cylinder 22, which can generate turbulence and mix the asphalt, so that the added water can be evenly dispersed into the molten asphalt.

[0063] Furthermore, in the above embodiments, an example was described in which obstacles 26a and 26b were provided in the connecting part 25 of the mixing section 21. However, even when there are no obstacles 26a and 26b in the connecting part 25, the molten asphalt with added water introduced from the inlet 23 into the cylinder 22 collides with the column 27 penetrating the cylinder 22, thereby generating turbulence and mixing in the cylinder 22, so that the added water is evenly dispersed into the molten asphalt.

[0064] Furthermore, in the above embodiment, an example of a cylindrical body 27 with a circular cross-section penetrating the cylinder 22 was described. However, as long as the molten asphalt with added water flowing down from the inlet 23 to the outlet 24 can collide with the cylindrical body 27 inside the cylinder 22, it is not limited to a circular cross-section. For example, a cylindrical body 27 with a square prism or a polygonal prism can also penetrate the cylinder 22 and be stirred and mixed inside the cylinder 22, so that the added water can be evenly dispersed into the molten asphalt.

[0065] Furthermore, the asphalt plant 1 can switch between the presence and absence of water spraying from the water nozzle 20. When manufacturing an asphalt mixture using ordinary (unwater-free) molten asphalt as raw material in the asphalt plant 1, the asphalt metering supply device 11 supplies molten asphalt metered by the asphalt metering tank 17 to the mixer 10 without spraying water from the water nozzle 20, thereby enabling the manufacture of ordinary asphalt mixtures and flexibly handling the manufacture of asphalt mixtures using both foamed asphalt and ordinary molten asphalt as raw materials.

[0066] Furthermore, compared with previous operation control, there are no major changes except for the water spray control from the water nozzle 20. For existing asphalt plants, the molten asphalt can be foamed simply by adding the water nozzle 20 and the mixing unit 21 to the asphalt supply pipe 19. It can be set up relatively simply and cheaply. Therefore, it can be properly adopted even in the case of existing asphalt plants.

[0067] Alternatively, the water nozzles 20 connected to the asphalt supply pipe 19 for spraying water onto the molten asphalt can be configured and connected at opposite positions on the asphalt supply pipe 19, or multiple water nozzles 20 can be configured and connected at a predetermined angle offset in the circumferential direction of the asphalt supply pipe 19. As long as water can be sprayed onto the flowing molten asphalt, various modifications can be made.

[0068] Industrial availability

[0069] This invention can be widely used in asphalt plants that manufacture asphalt mixtures that use foamed asphalt as a raw material.

Claims

1. An asphalt plant comprising a vibrating screen, aggregate storage bins, aggregate metering tanks, and a mixer assembled in a multi-tiered manner on an elevated platform, and equipped with asphalt supply piping and a supply pump for supplying molten asphalt metered by the asphalt metering tank to the mixer, characterized in that, A water nozzle is installed on the downstream side of the asphalt supply pipeline to inject water into the molten asphalt. A mixing section for mixing water and molten asphalt is provided on the downstream side of the asphalt supply pipe, where the water nozzle is located. The mixing section has a cylindrical body with a larger diameter than the asphalt supply pipe. The inlet and outlet are connected to the two ends of the cylinder by means of a funnel-shaped connecting part. The inlet and outlet are connected to the cylinder in such a way that their respective central axes are offset. On the other hand, the column is made to pass through the middle position of the cylinder in the downward flow direction in a direction orthogonal to the downward flow direction. After stirring and mixing the molten asphalt with added water flowing down the cylinder, it is supplied to the mixer.

2. The asphalt plant according to claim 1, characterized in that, Obstacles are provided on the inner wall surface of the connecting part that connects the cylinder to the inlet and the outlet, respectively, to prevent the flow of water and molten asphalt flowing down into the cylinder.

3. The asphalt plant according to claim 2, characterized in that, The obstruction on the inlet side protrudes from the inner wall surface of the connecting part that connects the cylinder and the inlet portion toward the space between the inlet portion and the column, and the obstruction on the outlet side protrudes from the inner wall surface of the connecting part that connects the cylinder and the outlet portion toward the space between the outlet portion and the column.

4. The asphalt plant according to any one of claims 1 to 3, characterized in that, The central axis of the inlet and the central axis of the outlet are located on opposite sides of each other, separated by the central axis of the cylinder.

5. The asphalt plant according to any one of claims 1 to 3, characterized in that, The asphalt plant is able to switch between the presence and absence of water sprayed from the water nozzles.

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