Fine aggregate screening equipment and screening method for recycled asphalt mixture

Abstract

The invention relates to the technical field of recycled asphalt mixture screening, and provides recycled asphalt mixture fine aggregate screening equipment and method.The recycled asphalt mixture fine aggregate screening equipment comprises a machine shell and at least two layers of vibrating screen bodies sequentially arranged in the machine shell from top to bottom, and screen meshes of all the layers of vibrating screen bodies are sequentially reduced from top to bottom; each layer of vibrating screen body comprises at least two vibrating screen meshes which are sequentially and obliquely arranged downwards in the length direction, screen mesh fixing mechanisms are arranged at the positions, corresponding to the two ends of each vibrating screen mesh, in the machine shell, and the two ends of each vibrating screen mesh are connected with the screen mesh fixing mechanisms; the tail end of the front vibrating screen is positioned above the head end of the rear vibrating screen; a high-frequency vibration mechanism is arranged in the machine shell and corresponds to the middle of each vibrating screen, and the high-frequency vibration mechanisms abut against the lower surfaces of the vibrating screens. The recycled asphalt mixture screening device has the advantages that the recycled asphalt mixture can be prevented from adhering and pasting meshes of the screen, fine aggregate with the particle size smaller than 5 mm can be well screened, and the screening effect is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of regenerated asphalt mixture screening, and in particular to a fine aggregate screening device and a screening method for regenerated asphalt mixture. Background Art

[0002] Recycled asphalt mixture refers to the mixture that is reused after the old asphalt pavement is dug up, recycled, crushed and screened. By recycling recycled asphalt mixture, a large amount of raw materials such as asphalt and sand and gravel can be saved, which has significant economic, social and environmental benefits.

[0003] After crushing, the recycled asphalt mixture usually needs to be screened into three to five specifications, and the more screening specifications, the higher the utilization rate of the recycled asphalt mixture. Because the recycled asphalt mixture contains asphalt, it becomes extremely difficult to screen fine aggregates below 5 mm. In the process of screening fine aggregates below 5 mm in the existing screening equipment, it is easy for the mesh of the screen to be blocked, resulting in the inability to screen normally. In view of the above-mentioned problems, the inventor of this case conducted an in-depth study on the problem, and thus this case was created. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a fine aggregate screening device and a screening method for recycled asphalt mixture, so as to solve the problem that in the process of screening fine aggregates below 5 mm by the existing screening equipment, the sieve holes of the sieve are easily blocked, thus causing the inability to screen normally.

[0005] The present invention is achieved in that: In the first aspect, a fine aggregate screening device for recycled asphalt mixture comprises a casing and at least two layers of vibrating screen bodies arranged in sequence from top to bottom in the casing, the mesh openings of the vibrating screen bodies in each layer decreasing in sequence from top to bottom; each layer of the vibrating screen bodies comprises at least two vibrating screen meshes arranged in sequence and tilted downward along the length direction, screen fixing mechanisms are arranged at both end positions corresponding to each vibrating screen mesh in the casing, both ends of each vibrating screen mesh are connected to the screen fixing mechanisms, and the end of the previous vibrating screen mesh is located above the head end of the next vibrating screen mesh; a high-frequency vibration mechanism is arranged in the casing at the middle position corresponding to each vibrating screen mesh, the top of the high-frequency vibration mechanism abuts against the lower surface of the vibrating screen mesh and makes the vibrating screen mesh present a bow-shaped structure.

[0006] Furthermore, two high-frequency vibration mechanisms are disposed at the top of the middle part of the lower surface of each vibrating screen.

[0007] Furthermore, the screen fixing mechanism includes a fixed hook and an adjustable hook; Fixed beams are provided at both ends of each vibrating screen in the casing, and the ends of two adjacent vibrating screens facing each other share a common fixed beam; one end of each vibrating screen is hooked on a fixed hook, and the other end of each vibrating screen is hooked on an adjustable hook; the fixed hook and the adjustable hook are arranged on the fixed beam.

[0008] Furthermore, the adjustable pull hook includes a hook body, a movable rod, a locking nut and a fixed tube, and the fixed tube is fixed on the fixed beam; the movable rod passes through the interior of the fixed tube, one end of the movable rod is connected to the hook body, and the outer surface of the other end of the movable rod is provided with an external thread section, and the other end of the movable rod is locked by a locking nut.

[0009] Furthermore, each layer of the vibrating screen body includes three vibrating screen meshes arranged downwardly in sequence along the length direction, wherein the upper and lower ends of the first vibrating screen mesh are provided with curved hooks facing downward, the upper ends of the second and third vibrating screen meshes are provided with curved hooks facing upward, and the lower ends of the second and third vibrating screen meshes are provided with curved hooks facing downward.

[0010] Furthermore, the vibrating screen includes an elastic outer frame and a plurality of transverse ribs and a plurality of longitudinal ribs woven in the elastic outer frame; the transverse ribs are corrugated steel wires, and at least one longitudinal rib is woven at every 3 to 5 wave peaks on the transverse ribs; the screen area formed by weaving the transverse ribs and the longitudinal ribs does not cover the area where the fixed beam is located.

[0011] Furthermore, the high-frequency vibration mechanism includes a vibration beam, an elastic vibration bar, a high-frequency vibration motor, a shock absorber, a material flow detector, a PLC control unit and a frequency conversion controller; Both ends of the vibration beam are connected to the casing through shock absorbers; a motor protection structure is provided at the bottom of the vibration beam, and the high-frequency vibration motor is arranged in the motor protection structure; elastic vibration strips are provided on both sides of the top of the vibration beam, and the elastic vibration strips are connected to the vibration beam through a mounting structure, and the top of the elastic vibration strips abuts against the lower surface of the vibration screen; the upper and lower surfaces of the vibration screen are equipped with material flow detectors, the material flow detector is connected to the PLC control unit, the PLC control unit is connected to the frequency conversion controller, and the frequency conversion controller is connected to the high-frequency vibration motor; Among the endpoints at both ends of the top surface of the vibration screen and the contact points between each elastic vibration strip and the lower surface of the vibration screen, the middle point of any three adjacent points is located above the line connecting the front and rear points.

[0012] Furthermore, the casing is provided with a first discharge port at the end position corresponding to each layer of the vibrating screen body, and the casing is provided with a feed opening at the head end position corresponding to the uppermost layer of the vibrating screen body; A collecting hopper is arranged inside the casing below the lowermost vibrating screen body, and the inner bottom of the collecting hopper forms a slope with an inclination angle greater than 70°; the collecting hopper is provided with a second discharge port at the position corresponding to the lowest end of the slope, and the second discharge port is equipped with a discharge belt conveyor.

[0013] In a second aspect, a screening method of a fine aggregate screening device for a recycled asphalt mixture is provided, the screening method comprising the following steps: After the equipment is turned on, the material flow of each vibrating screen is detected in real time; The required vibration frequency is calculated according to the detected material flow, and the high-frequency vibration mechanism is controlled according to the required vibration frequency to drive the corresponding vibration screen to vibrate.

[0014] Furthermore, the vibration frequency of the high-frequency vibration mechanism is 30-100 Hz, and the amplitude is 0.3-1.5 mm.

[0015] By adopting the technical solution of the present invention, at least the following beneficial effects are achieved: 1. Each layer of the vibrating screen body is designed to include at least two vibrating screens that are arranged in a downward slant along the length direction, both ends of the vibrating screens are connected to the screen fixing mechanism, and a high-frequency vibration mechanism is provided in the middle of each vibrating screen; so that in specific work, the high-frequency vibration mechanism can be used to drive the vibrating screen to vibrate at high frequency, so that the speed at which the recycled asphalt mixture adheres to the screen is less than the escape speed of the screen, thereby avoiding the recycled asphalt mixture from sticking to the mesh of the screen, and can well realize the screening of fine aggregates below 5mm; at the same time, each layer of the vibrating screen body is composed of multiple independent vibrating screens, and each vibrating screen is driven by an independent high-frequency vibration mechanism to vibrate at high frequency, which can ensure the vibration effect.

[0016] 2. The screen fixing mechanism is designed to include a fixed hook and an adjustable hook, and the two ends of each vibrating screen are hooked on the fixed hook and the adjustable hook respectively. In the specific use process, on the one hand, the adjustable hook can be used to realize the tension adjustment of the vibrating screen, so that the vibrating screen can be tightly attached to the high-frequency vibration mechanism, ensuring that the high-frequency vibration mechanism can better drive the vibrating screen to vibrate at high frequency; on the other hand, the use of the hook can facilitate the replacement and maintenance of the vibrating screen.

[0017] 3. The transverse reinforcement of the vibrating screen is designed to be corrugated steel wire, and longitudinal reinforcement is woven at every 3 to 5 wave peaks on the transverse reinforcement. Since the corrugated steel wire has good elasticity and both ends of the transverse reinforcement are fixed on the elastic outer frame, the transverse reinforcement will be stretched during the vibration process, thereby compensating for the deformation of the vibrating screen along the length direction during the vibration process, which can effectively improve the service life of the vibrating screen and help the recycled asphalt mixture with a particle size smaller than the mesh specification to fall down quickly, avoiding the recycled asphalt mixture from sticking to the mesh of the screen; and because the high-frequency vibration mechanism is located in the middle of the vibrating screen, only the middle of the vibrating screen will vibrate at high frequency during operation, and the screen fixing mechanisms at both ends of the vibrating screen will hardly vibrate, which can ensure the vibration effect; at the same time, because the fixed beam is fixed, the screen area formed by the weaving of the transverse reinforcement and the longitudinal reinforcement is designed not to cover the area where the fixed beam is located, which can avoid the recycled asphalt mixture from falling down and sticking to the fixed beam.

[0018] 4. By equipping the upper and lower surfaces of the vibrating screen with material flow detectors, connecting the material flow detectors with the frequency converter through the PLC control unit, and connecting the frequency converter with the high-frequency vibration motor, during the specific working process, the PLC control unit can control the frequency converter to output different vibration frequencies to the high-frequency vibration motor according to the material flow conditions detected by the material flow detector, so that the high-frequency vibration motor can drive the vibrating screen to vibrate at a suitable vibration frequency, ensuring that there will be no sticking of materials and no damage to the vibrating screen due to excessive vibration force when no-load; at the same time, both ends of the vibration beam are connected to the casing through shock absorbers, which can reduce the transmission of vibration force to the casing and help reduce vibration noise; and the high-frequency vibration motor is equipped with a motor protection structure to prevent the recycled asphalt mixture from falling onto the high-frequency vibration motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with embodiments with reference to the accompanying drawings.

[0020] Figure 1 It is an overall structural diagram of a fine aggregate screening device for recycled asphalt mixture of the present invention; Figure 2 It is an internal structure diagram of a fine aggregate screening device for recycled asphalt mixture of the present invention; Figure 3 It is a structural diagram of a single-layer vibrating screen body of the present invention; Figure 4 yes Figure 3 A magnified view of the middle A area; Figure 5 yes Figure 3 Enlarged view of the B area; Figure 6 yes Figure 3 Enlarged view of the middle C area; Figure 7It is a structural diagram of a fixed beam provided with an adjustable draw hook according to the present invention; Figure 8 It is a structural diagram of a fixed beam provided with a fixed draw hook according to the present invention; Fig. 9 is a cross-sectional view of the high-frequency vibration mechanism of the present invention; Fig.10 It is a bottom structural diagram of the high-frequency vibration mechanism of the present invention; Fig.11 It is a structural diagram of the high-frequency vibration mechanism of the present invention after removing the side baffles; Fig.12 is a structural diagram of the vibrating screen of the present invention; Fig.13 It is an assembly structure diagram of the collecting hopper and the discharging belt conveyor of the present invention; Fig.14 It is a control principle block diagram of the high-frequency vibration mechanism of the present invention.

[0021] Description of reference numerals: Fine aggregate screening equipment 100; Casing 1, first discharge port 11, feed opening 12, collecting hopper 13, inclined surface 131, discharge belt conveyor 14; Vibrating screen body 2, vibrating screen mesh 21, hook portion 211, elastic outer frame 212, transverse ribs 213, longitudinal ribs 214; Screen fixing mechanism 3, fixed hook 31, adjustable hook 32, hook body 321, movable rod 322, locking nut 323, fixing cylinder 324; High-frequency vibration mechanism 4, vibration beam 41, elastic vibration strip 42, high-frequency vibration motor 43, shock absorber 44, material flow detector 45, PLC control unit 46, frequency conversion controller 47, motor protection structure 48, second mounting main board 481, side baffle 482, narrowing area 483, mounting structure 49, first mounting main board 491, second connecting plate 492, pressing plate 493, support strip 494; Fixed beam 5 , first connecting plate 51 , bending plate 52 , square supporting tube 53 . DETAILED DESCRIPTION

[0022] In order to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0023] It should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing these embodiments and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. In addition, the terms "first", "second", etc., etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. Embodiment 1

[0024] See also Figures 1 to 14 As shown, the present invention is a fine aggregate screening device 100 for regenerated asphalt mixture, the fine aggregate screening device 100 comprises a casing 1 and at least two layers of vibrating screen bodies 2 arranged in sequence from top to bottom in the casing 1, the mesh openings of the vibrating screen bodies 2 of each layer decrease from top to bottom, so as to screen out fine aggregates of various specifications; Each layer of the vibrating screen body 2 includes at least two vibrating screens 21 arranged in a downwardly inclined manner in sequence along the length direction. Screen fixing mechanisms 3 are provided at the two end positions corresponding to each vibrating screen 21 in the casing 1. Both ends of each vibrating screen 21 are connected to the screen fixing mechanisms 3, and the end of the previous vibrating screen 21 is located above the head end of the next vibrating screen 21, so that the recycled asphalt mixture can smoothly fall from the previous vibrating screen 21 to the next vibrating screen 21; a high-frequency vibration mechanism 4 is provided in the casing 1 at the middle position corresponding to each vibrating screen 21, and the top of the high-frequency vibration mechanism 4 abuts against the lower surface of the vibrating screen 21 and makes the vibrating screen 21 present a bow-shaped structure.

[0025] The present invention is designed that each layer of the vibrating screen body 2 includes at least two vibrating screens 21 which are arranged to be inclined downward in sequence along the length direction, both ends of the vibrating screen 21 are connected to the screen fixing mechanism 3, and a high-frequency vibration mechanism 4 is arranged in the middle of each vibrating screen 21; so that during specific operation, the high-frequency vibration mechanism 4 can be used to drive the vibrating screen 21 to vibrate at high frequency, so that the speed at which the recycled asphalt mixture adheres to the screen is lower than the escape speed of the screen, thereby preventing the recycled asphalt mixture from adhering to and blocking the mesh of the screen, and can well realize the screening of fine aggregates below 5 mm; at the same time, each layer of the vibrating screen body 2 is composed of a plurality of independent vibrating screens 21, and each vibrating screen 21 is driven by an independent high-frequency vibration mechanism 4 to vibrate at high frequency, which can ensure the vibration effect.

[0026] As a specific implementation of the present invention, two high-frequency vibration mechanisms 4 are disposed against the middle of the lower surface of each vibrating screen 21 to ensure that the middle of each vibrating screen 21 can reliably and effectively vibrate. Of course, the above is only a specific implementation of the present invention, but the present invention is not limited thereto, and the number of high-frequency vibration mechanisms 4 can be adjusted according to actual needs during specific implementation.

[0027] In some embodiments of the present invention, the screen fixing mechanism 3 includes a fixed hook 31 and an adjustable hook 32; Fixed beams 5 are provided at both ends of each vibrating screen 21 in the casing 1, and the ends of two adjacent vibrating screens 21 facing each other share a common fixed beam 5, which can not only reduce the equipment cost, but also enable the two adjacent vibrating screens 21 to be better connected together, ensuring that the recycled asphalt mixture can transition from the previous vibrating screen 21 to the next vibrating screen 21; one end of each vibrating screen 21 is hooked on the fixed hook 31, and the other end of each vibrating screen 21 is hooked on the adjustable hook 32; the fixed hook 31 and the adjustable hook 32 are arranged on the fixed beam 5.

[0028] The present invention designs a screen fixing mechanism 3 including a fixed hook 31 and an adjustable hook 32, and hooks the two ends of each vibrating screen 21 onto the fixed hook 31 and the adjustable hook 32 respectively, so that during specific use, on the one hand, the adjustable hook 32 can be used to realize the tensioning and adjustment of the vibrating screen 21, so that the vibrating screen 21 can be tightly attached to the high-frequency vibration mechanism 4, ensuring that the high-frequency vibration mechanism 4 can better drive the vibrating screen 21 to vibrate at high frequency; on the other hand, the use of the hook can facilitate the replacement, maintenance and other operations of the vibrating screen 21.

[0029] As the first specific implementation of the present invention, please refer to Figure 5 and Figure 6 As shown, the fixed beam 5 includes two first connecting plates 51 and a bending plate 52 connected between the two first connecting plates 51, the first connecting plates 51 are fixed on the casing 1, and the bending plate 52 serves as a fixed hook 31, that is, the bending plate 52 serves as both a fixed beam 5 and a fixed hook 31 to simplify the overall structure and reduce costs; the fixed beam 5 of the first specific embodiment is suitable for being arranged between two adjacent vibrating screens 21.

[0030] As the second specific implementation of the present invention, please refer to Figure 4As shown, the fixed beam 5 includes two first connecting plates 51 and a square support tube 53 connected between the two first connecting plates 51; the fixed beam 5 of the second specific embodiment is suitable for being arranged at the upper end of the first vibrating screen 21 or the lower end of the last vibrating screen 21.

[0031] As a specific implementation of the present invention, please focus on Figure 6 and Figure 7 As shown, the adjustable hook 32 includes a hook body 321, a movable rod 322, a locking nut 323 and a fixed cylinder 324, and the fixed cylinder 324 is fixed on the fixed beam 5; the movable rod 322 passes through the interior of the fixed cylinder 324, one end of the movable rod 322 is connected to the hook body 321, and the outer surface of the other end of the movable rod 322 is provided with an external thread section (not shown), and the other end of the movable rod 322 is locked by the locking nut 323. When the adjustable hook 32 of the present invention is used, the locking nut 323 can be rotated to drive the hook body 321 to be movable and adjusted, so that the hook body 321 can tighten or loosen the vibrating screen 21.

[0032] As a specific implementation of the present invention, please focus on Figure 3 As shown, each layer of the vibrating screen body 2 includes three vibrating screens 21 arranged in a downwardly inclined manner in sequence along the length direction, wherein the upper and lower ends of the first vibrating screen 21 are provided with hook portions 211 facing downward, the upper ends of the second and third vibrating screens 21 are provided with hook portions 211 facing upward, and the lower ends of the second and third vibrating screens 21 are provided with hook portions 211 facing downward. Of course, the above is only a specific embodiment of the present invention, but the present invention is not limited thereto. In specific implementation, the number of vibrating screens 21 included in each layer of the vibrating screen body 2 can also be adjusted according to actual needs. At the same time, when the number of vibrating screens 21 included in each layer of the vibrating screen body 2 is greater than 3, it is necessary to make the hook portions 211 at the upper ends of the second and subsequent vibrating screens 21 face upward, and the hook portions 211 at the lower ends face downward.

[0033] When the single-layer vibrating screen body 2 of the present invention is working, the high-frequency vibration mechanism 4 in contact with the lower surface of the vibrating screen 21 will drive the vibrating screen 21 to vibrate at high frequency. When the regenerated asphalt mixture enters the upper part of the first vibrating screen 21, the regenerated asphalt mixture will slide down obliquely along the screen surface of the first vibrating screen 21 to the second vibrating screen 21, and then slide down obliquely along the screen surface of the second vibrating screen 21 to the third vibrating screen 21, and finally slide down obliquely along the screen surface of the third vibrating screen 21 to the outlet and be output. At the same time, in this process, the regenerated asphalt mixture with a particle size smaller than the screen hole specification of this layer of vibrating screen body 2 will fall into the next layer of vibrating screen body 2 for further screening.

[0034] In some embodiments of the present invention, please refer to Fig.12 As shown, the vibration screen 21 includes an elastic outer frame 212 and a plurality of transverse ribs 213 and a plurality of longitudinal ribs 214 woven in the elastic outer frame 212, wherein the elastic outer frame 212 can ensure that the vibration screen 21 can bend upward to form a bow structure, and both ends of the transverse ribs 213 and the longitudinal ribs 214 are fixed on the elastic outer frame 212; the transverse ribs 213 are corrugated steel wires, and at least one longitudinal rib 214 is woven at every 3 to 5 wave peaks on the transverse ribs 213, and the longitudinal ribs 214 can specifically be straight steel wires; the screen area formed by weaving the transverse ribs 213 and the longitudinal ribs 214 does not cover the area where the fixed beam 5 is located.

[0035] The present invention designs the transverse ribs 213 of the vibrating screen 21 to be corrugated steel wires, and weaves longitudinal ribs 214 at intervals of 3 to 5 wave peaks on the transverse ribs 213. Since the corrugated steel wires have good elasticity, and both ends of the transverse ribs 213 are fixed on the elastic outer frame 212, the transverse ribs 213 will be stretched during the vibration process, thereby compensating for the deformation of the vibrating screen 21 along the length direction during the vibration process, which can effectively improve the service life of the vibrating screen 21 and also help to quickly move the recycled asphalt mixture with a particle size smaller than the mesh size. and because the high-frequency vibration mechanism 4 is arranged in the middle of the vibrating screen 21, only the middle of the vibrating screen 21 will vibrate at high frequency during operation, while the screen fixing mechanisms 3 at both ends of the vibrating screen 21 will hardly vibrate, thereby ensuring the vibration effect; at the same time, because the fixed beam 5 is fixed, the screen area formed by weaving the transverse reinforcement 213 and the longitudinal reinforcement 214 does not cover the area where the fixed beam 5 is located through design, which can prevent the recycled asphalt mixture from falling down and sticking to the fixed beam 5.

[0036] In some embodiments of the present invention, please refer to Figure 9-11 As shown, the high-frequency vibration mechanism 4 includes a vibration beam 41, an elastic vibration bar 42, a high-frequency vibration motor 43, a shock absorber 44, a material flow detector 45, a PLC control unit 46 and a frequency conversion controller 47; Both ends of the vibration beam 41 are connected to the housing 1 through shock absorbers 44, so that the shock absorbers 44 can be used to reduce the vibration force transmitted to the housing 1, which helps to reduce vibration noise; a motor protection structure 48 is provided at the bottom of the vibration beam 41, and the high-frequency vibration motor 43 is arranged in the motor protection structure 48, so that the motor protection structure 48 can protect the high-frequency vibration motor 43; elastic vibration strips 42 are provided on both sides of the top of the vibration beam 41, and the elastic vibration strips 42 are connected to the vibration beam 41 through a mounting structure 49 The top of the elastic vibration bar 42 abuts against the lower surface of the vibration screen 21. By using the elastic vibration bar 42 to abut against the lower surface of the vibration screen 21, the damage caused by the elastic vibration bar 42 to the vibration screen 21 during the vibration process can be effectively reduced; the upper and lower surfaces of the vibration screen 21 are equipped with a material flow detector 45, the material flow detector 45 is used to detect the material flow, the material flow detector 45 is connected to the PLC control unit 46, the PLC control unit 46 is connected to the frequency conversion controller 47, and the frequency conversion controller 47 is connected to the high-frequency vibration motor 43; At the endpoints at both ends of the top surface of the vibration screen 21 and the contact points between each elastic vibration strip 42 and the lower surface of the vibration screen 21, the middle point of any three adjacent points is located above the line connecting the front and rear points, so as to ensure that the entire vibration screen 21 can be reliably attached to the high-frequency vibration mechanism 4, thereby ensuring the vibration effect of the vibration screen 21.

[0037] Please refer to Fig.14 As shown, the high-frequency vibration mechanism 4 of the present invention can detect the material flow on the upper and lower surfaces of each vibrating screen 21 in real time through the material flow detector 45 during specific operation, and feed back the detection results to the PLC control unit 46 for calculation, and control the frequency conversion controller 47 to output different vibration frequencies to the high-frequency vibration motor 43 according to the calculation results, so that the high-frequency vibration motor 43 drives the vibrating screen 21 to vibrate according to the corresponding vibration frequency, thereby ensuring that the vibrating screen 21 always remains in the best working state. For example, when the present invention is implemented, when the equipment is turned on but no material is fed, the PLC control unit 46 can control the frequency conversion controller 47 to output 30Hz AC (i.e., the vibration frequency is 30Hz) to the high-frequency vibration motor 43 to avoid excessive vibration force of the vibrating screen 21 when it is unloaded, and cause damage to the vibrating screen 21. When feeding starts and the material flow detector 45 detects the material flow, the PLC control unit 46 controls the frequency converter controller 47 to output 50 Hz AC power to the high-frequency vibration motor 43, so that the vibration screen 21 can drive the regenerated asphalt mixture to vibrate at high frequency; at the same time, the material flow detector 45 continues to detect the material flow in real time, and the PLC control unit 46 performs real-time calculations on the detection results, and analyzes whether the regenerated asphalt mixture sticks to the screen and whether the screening is thorough, and then gives a suitable vibration frequency, and outputs the corresponding vibration frequency to the high-frequency vibration motor 43 through the frequency converter controller 47.

[0038] The present invention provides a material flow detector 45 on the upper and lower surfaces of the vibration screen 21, connects the material flow detector 45 to the frequency conversion controller 47 through a PLC control unit 46, and connects the frequency conversion controller 47 to the high-frequency vibration motor 43, so that in the specific working process, the PLC control unit 46 can control the frequency conversion controller 47 to output different vibration frequencies to the high-frequency vibration motor 43 according to the material flow conditions detected by the material flow detector 45, so that the high-frequency vibration motor 43 can drive the vibration screen 21 to vibrate at a suitable vibration frequency, ensuring that there will be no sticking of materials and no damage to the vibration screen 21 due to excessive vibration force when unloaded; at the same time, both ends of the vibration beam 41 are connected to the casing 1 through shock absorbers 44, which can reduce the transmission of vibration force to the casing 1 and help reduce vibration noise; and the high-frequency vibration motor 43 is provided with a motor protection structure 48 to prevent the recycled asphalt mixture from falling onto the high-frequency vibration motor 43.

[0039] As a specific embodiment of the present invention, the mounting structure 49 includes a first mounting main board 491 arranged on both sides of the vibration beam, a plurality of second connecting plates 492 connected between the two first mounting main boards 491, and a pressure plate 493; the middle part of each of the second connecting plates 492 is fixedly connected to the vibration beam 41; a support bar 494 is fixedly provided on the outer side of the first mounting main board 491, and the bottom of the elastic vibration bar 42 is supported on the top of the support bar 494; the pressure plate 493 blocks the outer side of the elastic vibration bar 42, and locks the pressure plate 493, the elastic vibration bar 42 and the first mounting main board 491 together. Specifically, the pressure plate 493, the elastic vibration bar 42 and the first mounting main board 491 can be locked together by bolts and nuts, so that the elastic vibration bar 42 can be conveniently disassembled and replaced during use.

[0040] As a specific embodiment of the present invention, the motor protection structure 48 includes a second mounting main board 481 fixedly arranged at the bottom of the vibration beam 41 and side baffles 482 arranged on both sides of the second mounting main board 481 along the length direction of the vibration beam 41. The high-frequency vibration motor 43 is locked and fixed to the bottom of the second mounting main board 481. Specifically, the high-frequency vibration motor 43 can be locked to the bottom of the second mounting main board 481 by bolts and nuts; the upper end of the side baffle 482 is locked and connected to the second mounting main board 481, and the lower end of the side baffle 482 is lower than the bottom of the high-frequency vibration motor 43, and a narrowing area 483 is formed at both ends between the second mounting main board 481 and the side baffles 482 on both sides.

[0041] The present invention designs the motor protection structure 48 to include a second mounting main board 481 and side baffles 482 arranged on both sides of the second mounting main board 481, and makes the lower ends of the side baffles 482 lower than the bottom of the high-frequency vibration motor 43, so that narrowed areas 483 are formed at both ends between the second mounting main board 481 and the side baffles 482 on both sides. This can not only prevent the recycled asphalt mixture from falling and sticking to the high-frequency vibration motor 43, but also the bottom of the motor protection structure 48 is open, which is conducive to heat dissipation and maintenance operations.

[0042] As a specific embodiment of the present invention, the shock absorber 44 adopts a rubber isolation bearing, which is a device used to improve the seismic resistance of the structure. The structure of the rubber isolation bearing usually includes multiple layers of steel plates and rubber alternately stacked. The steel plate is used as a stiffening material for the rubber bearing, which changes the characteristic of the rubber body's low vertical stiffness, so that it can both reduce horizontal vibration effects and withstand large vertical loads. The elastic vibration strip 42 is a rubber strip, specifically a hard rubber strip, which can better transmit the vibration force to the vibration screen 21 and reduce damage to the vibration screen 21; the vibration beam 41 adopts a hollow structure to reduce the weight of the vibration beam 41 and improve the vibration effect.

[0043] In some embodiments of the present invention, please refer to Figure 2 As shown, the housing 1 is provided with a first discharge port 11 at the end position corresponding to each layer of the vibrating screen body 2, and the regenerated asphalt mixture after each layer of screening is output through the corresponding first discharge port 11; the housing 1 is provided with a feed opening 12 at the head end position corresponding to the uppermost layer of the vibrating screen body 2, so as to transport the regenerated asphalt mixture into the fine aggregate screening device 100 through the feed opening 12; Please refer to Fig.13 As shown, a collecting hopper 13 is arranged inside the casing 1 below the corresponding lowest layer of the vibrating screen body 2, and the finest regenerated asphalt mixture after the lowest layer screening will fall into the collecting hopper 13; the inner bottom of the collecting hopper 13 is formed with a slope 131 with an inclination angle greater than 70°, so that the regenerated asphalt mixture can slide down along the slope 131 better, and avoid the regenerated asphalt mixture sticking to the bottom of the collecting hopper 13; the collecting hopper 13 is provided with a second discharge port (not shown) at the position corresponding to the lowest end of the slope 131, and the second discharge port is equipped with a discharge belt conveyor 14 to realize the discharge of the regenerated asphalt mixture in the collecting hopper 13 to the discharge belt conveyor 14.

[0044] As a specific embodiment of the present invention, two layers of vibrating screen bodies 2 are arranged in sequence from top to bottom in the casing 1. During the specific implementation, the fine aggregate of the regenerated asphalt mixture can be screened into three different specifications of 0~3mm, 3~5mm and greater than 5mm. Among them, the upper layer outputs the regenerated asphalt mixture greater than 5mm, the lower layer outputs the regenerated asphalt mixture of 3~5mm, and the aggregate hopper 13 outputs the regenerated asphalt mixture of 0~3mm. Embodiment 2

[0045] See also Figures 1 to 14 As shown, a screening method of a fine aggregate screening device 100 for regenerated asphalt mixture of the present invention, wherein the structure of the fine aggregate screening device and the technical effects that can be obtained are exactly the same as those of the first embodiment, and please refer to the detailed introduction of the first embodiment for details, which will not be repeated here; the screening method comprises the following steps: After the equipment is turned on, the material flow of each vibrating screen 21 is detected in real time; The required vibration frequency is calculated according to the detected material flow, and the high-frequency vibration mechanism 4 is controlled according to the required vibration frequency to drive the corresponding vibration screen 21 to vibrate. In the present invention, the vibration frequency of the high-frequency vibration mechanism 4 is 30-100 Hz, and the amplitude is 0.3-1.5 mm.

[0046] For example, in the specific implementation of the present invention, when the equipment is turned on but no material is fed, the PLC control unit 46 can control the frequency conversion controller 47 to output 30Hz AC power (i.e., the vibration frequency is 30Hz) to the high-frequency vibration motor 43 to avoid excessive vibration force of the vibrating screen 21 when unloaded and damage to the vibrating screen 21; when feeding starts and the material flow detector 45 detects the material flow, the PLC control unit 46 controls the frequency conversion controller 47 to output 50Hz AC power to the high-frequency vibration motor 43, so that the vibrating screen 21 can drive the recycled asphalt mixture to vibrate at high frequency; at the same time, the material flow detector 45 continues to detect the material flow in real time, and the PLC control unit 46 is used to perform real-time calculations on the detection results, and analyze whether the recycled asphalt mixture sticks to the screen and whether the screening is thorough, and then give a suitable vibration frequency, and output the corresponding vibration frequency to the high-frequency vibration motor 43 through the frequency conversion controller 47.

[0047] Although the specific implementation modes of the present invention are described above, those skilled in the art should understand that the specific implementation modes described are only illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A fine aggregate screening device for recycled asphalt mixture, comprising a housing and at least two layers of vibrating screen bodies arranged in sequence from top to bottom in the housing, wherein the mesh openings of the vibrating screen bodies in each layer decrease in sequence from top to bottom; characterized in that: Each layer of the vibrating screen body includes at least two vibrating screens which are arranged to be inclined downward in sequence along the length direction. Screen fixing mechanisms are provided at both ends of each vibrating screen in the casing, both ends of each vibrating screen are connected to the screen fixing mechanisms, and the end of the previous vibrating screen is located above the head end of the next vibrating screen; a high-frequency vibration mechanism is provided in the casing at the middle position corresponding to each vibrating screen, and the top of the high-frequency vibration mechanism abuts against the lower surface of the vibrating screen and makes the vibrating screen present a bow-shaped structure.

2. The fine aggregate screening device for recycled asphalt mixture according to claim 1, characterized in that: Two high-frequency vibration mechanisms are arranged at the top in the middle of the lower surface of each vibrating screen.

3. The fine aggregate screening device for recycled asphalt mixture according to claim 1, characterized in that: The screen fixing mechanism includes a fixed hook and an adjustable hook; Fixed beams are provided at both ends of each vibrating screen in the casing, and the ends of two adjacent vibrating screens facing each other share a common fixed beam; one end of each vibrating screen is hooked on a fixed hook, and the other end of each vibrating screen is hooked on an adjustable hook; the fixed hook and the adjustable hook are arranged on the fixed beam.

4. The fine aggregate screening device for recycled asphalt mixture according to claim 3, characterized in that: The adjustable pull hook includes a hook body, a movable rod, a locking nut and a fixed tube, wherein the fixed tube is fixed on a fixed beam; the movable rod passes through the interior of the fixed tube, one end of the movable rod is connected to the hook body, and the outer surface of the other end of the movable rod is provided with an external thread section, and the other end of the movable rod is locked by a locking nut.

5. The fine aggregate screening device for recycled asphalt mixture according to claim 1, characterized in that: Each layer of the vibrating screen body includes three vibrating screen meshes which are arranged to be inclined downward in sequence along the length direction, wherein the upper and lower ends of the first vibrating screen mesh are provided with curved hooks facing downward, the upper ends of the second and third vibrating screen meshes are provided with curved hooks facing upward, and the lower ends of the second and third vibrating screen meshes are provided with curved hooks facing downward.

6. The fine aggregate screening device for recycled asphalt mixture according to claim 3, characterized in that: The vibrating screen comprises an elastic outer frame and a plurality of transverse ribs and a plurality of longitudinal ribs woven in the elastic outer frame; the transverse ribs are corrugated steel wires, and at least one longitudinal rib is woven at intervals of 3 to 5 wave peaks on the transverse ribs; the screen area formed by weaving the transverse ribs and the longitudinal ribs does not cover the area where the fixed beam is located.

7. The fine aggregate screening device for recycled asphalt mixture according to claim 1, characterized in that: The high-frequency vibration mechanism includes a vibration beam, an elastic vibration bar, a high-frequency vibration motor, a shock absorber, a material flow detector, a PLC control unit and a frequency conversion controller; Both ends of the vibration beam are connected to the casing through shock absorbers; a motor protection structure is provided at the bottom of the vibration beam, and the high-frequency vibration motor is arranged in the motor protection structure; elastic vibration strips are provided on both sides of the top of the vibration beam, and the elastic vibration strips are connected to the vibration beam through a mounting structure, and the top of the elastic vibration strips abuts against the lower surface of the vibration screen; the upper and lower surfaces of the vibration screen are equipped with material flow detectors, the material flow detector is connected to the PLC control unit, the PLC control unit is connected to the frequency conversion controller, and the frequency conversion controller is connected to the high-frequency vibration motor; Among the endpoints at both ends of the top surface of the vibration screen and the contact points between each elastic vibration strip and the lower surface of the vibration screen, the middle point of any three adjacent points is located above the line connecting the front and rear points.

8. The fine aggregate screening device for recycled asphalt mixture according to claim 1, characterized in that: The casing is provided with a first discharge port at the end position corresponding to each layer of the vibrating screen body, and the casing is provided with a feed opening at the head end position corresponding to the uppermost layer of the vibrating screen body; A collecting hopper is arranged inside the casing below the lowermost vibrating screen body, and the inner bottom of the collecting hopper forms a slope with an inclination angle greater than 70°; the collecting hopper is provided with a second discharge port at the position corresponding to the lowest end of the slope, and the second discharge port is equipped with a discharge belt conveyor.

9. A screening method for fine aggregate screening equipment of recycled asphalt mixture based on any one of claims 1 to 8, characterized in that: The screening method comprises the following steps: After the equipment is turned on, the material flow of each vibrating screen is detected in real time; The required vibration frequency is calculated according to the detected material flow, and the high-frequency vibration mechanism is controlled according to the required vibration frequency to drive the corresponding vibration screen to vibrate.

10. The screening method of the fine aggregate screening equipment of the regenerated asphalt mixture according to claim 9, characterized in that: The vibration frequency of the high-frequency vibration mechanism is 30-100 Hz, and the amplitude is 0.3-1.5 mm.

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