Multi-stage screening device and method for sand and gravel aggregate treatment

Abstract

The application discloses a multi-stage screening device and method for sand and gravel aggregate treatment, relates to the technical field of sand and gravel aggregate screening, and comprises a material transfer warehouse, a discharging port intelligent adjusting device, a warehouse-under belt coarse screening mechanism, a crusher, a transfer bin material control unit, a three-cavity gap adjusting mechanism of the crusher, a molding rate detection unit, a secondary screening mechanism and an intelligent control center. The application adopts a technical chain of non-contact detection-intelligent linkage-data closed loop, solves the problems of detection lag, rough adjustment and high energy consumption in traditional processes, realizes accurate, flexible and green production of sand and gravel aggregate grading, provides a high-performance aggregate solution for the fields of building and traffic, and has remarkable economic and social benefits.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of sand and gravel aggregate screening, for example to a multi-stage screening device and method for sand and gravel aggregate treatment. BACKGROUND

[0002] As a basic material for building engineering, the particle size gradation of sand and gravel aggregate directly affects the key performance of concrete strength and roadbed stability. In the traditional sand and gravel aggregate production process, the gradation control mainly relies on manual experience to adjust the parameters of the crusher and the screen mesh combination, and the following problems exist.

[0003] The detection means is backward, the raw material crushing value detection needs to be sampled and sent for inspection, the efficiency is low and the material integrity is damaged, and the production cannot be guided in real time.

[0004] The process is extensive, the gap between the crusher cavities is fixed or manually adjusted, it is difficult to match the hardness change of the raw material, and it is easy to cause over-crushing or uneven particle size.

[0005] The screening precision is insufficient, the screen mesh is mainly fixed aperture, the switching gradation mode needs to be replaced, and the differentiated needs of customers cannot be met.

[0006] The energy consumption is high, the return material rate control relies on manual experience, the repeated crushing of oversized aggregate increases energy consumption, and the unit power consumption is as high as 5-8 kWh / ton.

[0007] Data island, production parameters are disconnected with customer needs, quality traceability is difficult, and order response cycle is long. SUMMARY

[0008] In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not a general review, nor is it intended to determine the key / important components or delineate the protection scope of these embodiments, but as a prelude to the detailed description below.

[0009] In order to solve the above technical problems, the application provides a multi-stage screening device and method for sand and gravel aggregate treatment; the multi-stage screening device for sand and gravel aggregate treatment adopts a technical chain of non-contact detection-intelligent linkage-data closed loop, solves the problems of detection lag, rough adjustment, high energy consumption and the like in the traditional process, realizes the precision, flexibility and green production of sand and gravel aggregate gradation, provides a high-performance aggregate solution for the fields of building, transportation and the like, and has significant economic and social benefits.

[0010] The multi-stage screening device for sand and gravel aggregate treatment provided by the application comprises a material transfer warehouse, a discharging port intelligent adjusting device, a warehouse-under belt coarse screening mechanism, a crusher, a transfer bin control unit, a crusher three-cavity gap adjusting mechanism, a molding rate detection unit, a two-stage screening mechanism and an intelligent control center.

[0011] The material transfer warehouse is internally provided with a crushing value testing mechanism, the crushing value testing mechanism comprises a non-contact spectral analyzer, and the emission end and the receiving end of the non-contact spectral analyzer are respectively installed at symmetrical positions of the inner wall of the material transfer warehouse, which is used for detecting the compression strength of raw materials in real time and generating testing data;

[0012] The intelligent adjusting device of the discharging port comprises an electric gate valve, a servo motor I and a controller which are connected with the flange of the discharging port of the material transfer warehouse, the controller receives the testing data through a Profinet bus and drives the servo motor I to adjust the opening degree of the gate valve so as to control the proportion of coarse and fine aggregates.

[0013] The warehouse lower belt coarse screening mechanism is arranged directly below the electric gate valve and comprises a first-level vibrating screen with an inclination angle of 15°-30° and a return material transfer belt, the screen hole diameter of the first-level vibrating screen is 20 mm, the super-particle-diameter aggregate is slid into the return material transfer belt through a chute, the end of the return material transfer belt is connected to the feeding port of the crusher through a material guide chute, and a buffer baffle is arranged in the material guide chute.

[0014] The transfer bin control unit comprises a transfer bin, a material level sensor and a variable frequency feeder, the bottom of the transfer bin is connected to the variable frequency feeder through a corrugated pipe, and the discharging port of the variable frequency feeder is connected to the feeding port of the crusher through a sealed chute;

[0015] The three-cavity gap adjusting mechanism of the crusher comprises an upper cavity, a middle cavity and a lower cavity, the gap between each cavity is independently adjusted by a servo motor II driven hydraulic connecting rod, and the adjusting precision is ±0.5 mm.

[0016] The forming rate detection unit is installed on the upper support of the discharging belt of the crusher and comprises a laser scanner, the scanning direction of the laser scanner is perpendicular to the surface of the belt, the scanning frequency is 2000 frames per second, and the detection data is transmitted to the intelligent control center through an optical fiber.

[0017] The secondary screening mechanism comprises a plurality of layers of fine screen meshes, a screen box, a vibration frequency adjustable vibrator and a pneumatic push rod, the plurality of layers of fine screen meshes are connected to the screen box through hinges, and the screen hole size is continuously adjusted in the range of 0.5 mm to 10 mm through the pneumatic push rod.

[0018] The intelligent control center comprises a PLC controller, a data cloud platform and an industrial router, the PLC controller receives the data of each module through a Modbus protocol and adjusts the opening degree of the electric gate valve, the crushing cavity gap and the screening parameters according to the preset rules.

[0019] In the further improvement of the application, the detection wavelength range of the non-contact spectral analyzer is 400-1000 nm, and the detection data is transmitted to the controller in real time through a Profinet bus.

[0020] The application further improves the L-shaped layout of the material return transfer belt and the main production line, and the inclination angle of the buffer baffle is 45 degrees, and the surface is covered with a polyurethane wear-resistant layer.

[0021] The application further improves that the servo motor II is connected with the adjusting bolt of the three-cavity crusher through a hydraulic connecting rod.

[0022] The application further improves that the laser scanner is built-in with an image recognition algorithm, including the following steps,

[0023] The aggregate image is subjected to gray scale processing;

[0024] The particle size contour is extracted through an edge detection algorithm;

[0025] The qualified rate is calculated and a feedback signal is generated to the PLC controller.

[0026] The application further improves that the stroke of the pneumatic push rod is 50-100 mm, the thrust is 200 N, and the vibration frequency of the multi-layer fine screen mesh vibrator is synchronously matched with the rotating speed of the crusher discharge belt through a frequency converter.

[0027] The application further improves that the data cloud platform is connected with the customer order system through an industrial router, the gradation parameters include the particle size distribution curve of continuous gradation or the particle size threshold value of discontinuous gradation, the platform automatically generates corresponding screen hole size instructions and sends them to the PLC controller.

[0028] The application further improves that the energy consumption optimization mechanism is further included, the mechanism includes a power sensor and an energy consumption analysis unit, and the power sensor monitors the current and voltage of the crusher in real time.

[0029] The application further improves that the variable frequency feeder of the transfer bin control unit is linked with the current sensor signal of the crusher, and when the load of the crusher exceeds 90% of the rated value, the feeding speed is automatically reduced to a preset safety threshold.

[0030] The application provides a screening method based on the multi-stage screening device for sand and gravel aggregate treatment, including the following steps,

[0031] In step S1, the non-contact crushing value of the raw material is detected by a non-contact spectrum analyzer in the material transfer warehouse, and the detection data is uploaded to the PLC controller in real time.

[0032] In step S2, the controller dynamically adjusts the opening degree according to the crushing value data, the coarse screening mechanism separates the oversized aggregate, and the oversized aggregate is returned to the crusher for crushing;

[0033] In step S3, the oversized aggregate is returned to the crusher through the material return transfer belt, and the return rate is monitored in real time by a flowmeter and fed back to the PLC controller.

[0034] Step S4, the servo motor II adjusts the middle cavity gap according to the crushing value data and the molding rate feedback, and the specific adjustment logic is as follows:

[0035] If the molding rate < 90%, the middle cavity gap is reduced by 2%;

[0036] If the molding rate is greater than or equal to 90%, the current gap is maintained;

[0037] Step S5, the pneumatic push rod adjusts the sieve hole size according to the grading parameter issued by the PLC controller, and the sieve holes are distributed in an arithmetic sequence in the continuous grading mode, and the sieve holes are segmented according to the preset threshold in the intermittent grading mode.

[0038] Step S6, the data cloud platform generates a production report containing the grading deviation, energy consumption and qualified rate, and pushes it to the customer terminal through the industrial router.

[0039] Compared with the prior art, the present application has the following beneficial effects:

[0040] The present application adopts the technical chain of non-contact detection-intelligent linkage-data closed loop, and solves the problems of detection lag, rough adjustment and high energy consumption in traditional processes, realizes the precise, flexible and green production of sand and gravel aggregate grading, provides high-performance aggregate solutions for the fields of building and transportation, and has significant economic and social benefits.

[0041] The foregoing general description and the following description are only exemplary and explanatory, and are not used to limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the background art or the technical scheme of the present application, the drawings used in the prior art or the specific embodiments are briefly introduced as follows: Obviously, the structure, proportion, size, etc. shown in the drawings are only used to cooperate with the content disclosed in the specification, so that those skilled in the art can understand and read, and are not used to limit the limiting conditions of the implementation of the present application, so they do not have technical significance. Any modification of structure, change of proportion relationship or adjustment of size, without affecting the effect and purpose that can be achieved by the present application, should still fall within the scope of the technical content disclosed by the present application.

[0043] Figure 1 The structure block diagram of the specific embodiment of the present application is shown in the following table.

[0044] Figure 2 The middle cavity gap formula according to the crushing value data of the specific embodiment of the present application is shown in the following table.

[0045] Figure 3 The energy consumption analysis unit data formula of the specific embodiment of the present application is shown in the following table.

[0046] Figure 4The formula of the feeding speed of the frequency conversion feeder and the crusher current data of the specific embodiment of the present application.

[0047] Figure 5 The controller calculates the opening of the electric gate valve according to the crushing value data of the specific embodiment of the present application. DETAILED DESCRIPTION

[0048] In order to enable persons skilled in the art to more fully understand the features and technical contents of the embodiments of the present application, the implementation of the embodiments of the present application is described in detail below with reference to the accompanying drawings, which are used for reference only and do not limit the embodiments of the present application; in the following technical description, in order to facilitate explanation, a plurality of details are provided to provide a full understanding of the disclosed embodiments; however, one or more embodiments can still be implemented without these details; in other cases, in order to simplify the drawings, well-known structures and devices can be simplified.

[0049] The terms "first", "second", and the like used in the embodiments of the present application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence; it should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented; in addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0050] In the embodiments of the present application, the terms "upper", "lower", "inner", "middle", "outer", "front", "back", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings; these terms are mainly used to better describe the embodiments of the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation; and in addition to indicating the orientation or positional relationship, the above-mentioned terms can also be used to indicate other meanings, for example, the term "upper" can also be used to indicate a certain attachment relationship or connection relationship in some cases; for those skilled in the art, the specific meanings of these terms in the embodiments of the present application can be understood according to the specific circumstances.

[0051] In addition, the terms "set", "connected", "fixed" should be broadly understood, for example, "connected" can be fixed connection, detachable connection, or integral structure; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through an intermediate medium, or internal communication between two devices, elements or components; for those skilled in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0052] Unless otherwise specified, the term "a plurality of" means two or more.

[0053] In the embodiments of the present application, the character " / " represents an "or" relationship between the preceding and following objects, for example, Z / X represents: Z or X; the term "and / or" is a description of the association between objects, which means that there can be three relationships, for example, Z and / or X, which means: Z or X, or, Z and X, the three relationships.

[0054] It should be noted that the embodiments in the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0055] Sand aggregate is a basic material for building engineering, and its particle size gradation directly affects the key performance of concrete strength and roadbed stability. In the traditional sand aggregate production process, the gradation control mainly relies on manual experience to adjust the parameters of the crusher and the screen combination, which has many problems.

[0056] Therefore, the design concept of the present application is to use the technology chain of non-contact detection-intelligent linkage-data closed loop to overcome the problems of detection lag, rough adjustment and high energy consumption in traditional processes, and to realize the precise, flexible and green production of sand aggregate gradation, providing high-performance aggregate solutions for the fields of building, transportation and other fields, which has significant economic and social benefits.

[0057] As shown in Figures 1-5 The present application provides a multi-stage screening device for sand aggregate treatment, which comprises a material transfer warehouse, a discharge port intelligent adjusting device, a warehouse under belt coarse screening mechanism, a crusher, a transfer bin control unit, a crusher three-cavity gap adjusting mechanism, a molding rate detection unit, a secondary screening mechanism and an intelligent control center.

[0058] The material transfer warehouse is internally provided with a crushing value testing mechanism, which comprises a non-contact spectral analyzer, and the emission end and the receiving end of the non-contact spectral analyzer are respectively installed at the symmetrical positions of the inner wall of the material transfer warehouse, for real-time detection of the compressive strength of the raw material and generation of test data.

[0059] The discharge port intelligent adjusting device comprises an electric gate valve connected with the discharge port flange of the material transfer warehouse, a servo motor I and a controller, the controller receives the test data through the Profinet bus, and controls the servo motor I to drive the adjusting gate valve opening to control the proportion of coarse and fine aggregate.

[0060] The material transfer warehouse is located at the starting end of the production line, and the discharge port intelligent adjusting device is vertically installed below the transfer warehouse to ensure that the material falls by gravity to the warehouse under belt coarse screening mechanism.

[0061] The under-silo belt coarse screening mechanism is located directly below the electric gate valve. It includes a primary vibrating screen with an inclination angle of 15°-30° and a return material conveyor belt. The screen aperture diameter of the primary vibrating screen is 20mm. Oversized aggregates slide into the return material conveyor belt through a chute. The end of the return material conveyor belt is connected to the crusher feed inlet through a guide chute, and the guide chute is equipped with a buffer baffle. The primary vibrating screen is installed at an inclination directly below the discharge port. Oversized aggregates on the screen slide into the return material conveyor belt through a chute. The end of the return material conveyor belt is connected to the crusher feed inlet through a guide chute, forming a closed-loop return path.

[0062] The transfer silo material control unit includes a transfer silo, a material level sensor, and a variable frequency feeder. The bottom outlet of the transfer silo is connected to the variable frequency feeder via a corrugated pipe flexible connection. The discharge port of the variable frequency feeder is connected to the feed port of the crusher via a sealed chute. The crusher current sensor signal is fed back to the variable frequency feeder via a cable to realize the linkage control between the feed rate and the crushing load.

[0063] The crusher has a three-chamber gap adjustment mechanism, including an upper chamber, a middle chamber, and a lower chamber. The gap between each chamber is independently adjusted by a servo motor II driving a hydraulic connecting rod, with an adjustment accuracy of ±0.5mm.

[0064] The crusher's discharge port is connected to the forming rate detection unit via a heavy-duty belt. A laser scanner is installed on the side of the heavy-duty belt, and the scanned data is transmitted to the intelligent control center via optical fiber.

[0065] Servo motor II is mechanically connected to the adjusting bolts of the upper, middle and lower chambers of the crusher via hydraulic connecting rods, enabling independent control of the chamber gaps.

[0066] The forming rate detection unit is installed on the support above the heavy-duty conveyor belt of the crusher discharge. It includes a laser scanner, whose scanning direction is perpendicular to the surface of the heavy-duty conveyor belt, and the scanning frequency is 2000 frames per second. The detection data is transmitted to the intelligent control center through optical fiber.

[0067] The forming rate detection unit is located downstream of the crusher, and the heavy-duty belt extends horizontally to the secondary screening mechanism, forming a straight material flow channel.

[0068] The secondary screening mechanism includes a multi-layer fine screen, a screen box, an adjustable vibration frequency vibrator, and a pneumatic push rod. The multi-layer fine screen is connected to the screen box via hinges, and the screen aperture size can be continuously adjusted within the range of 0.5mm to 10mm via the pneumatic push rod.

[0069] The fine screen of the secondary screening mechanism is hinged to the screen box via a pneumatic push rod. The screen vibration frequency is controlled by a frequency converter, and the frequency converter signal comes from the PLC controller of the intelligent control center.

[0070] The secondary screening mechanism is located at the end of the production line, close to the collection bin; the intelligent control center is independently located on the operation side of the production line for easy monitoring by personnel.

[0071] The intelligent control center comprises a PLC controller, a data cloud platform and an industrial router. The PLC controller receives data of each module through a Modbus protocol and adjusts the opening degree of the electrically operated gate valve, the gap between crushing cavities and the screening parameters according to preset rules.

[0072] The data cloud platform communicates with the PLC controller through the industrial router to realize remote parameter issuing and production monitoring.

[0073] The main path of the material is: raw materials from the material transfer warehouse→the intelligent adjustment device of the discharge port→the warehouse belt coarse screening mechanism→the transfer warehouse control unit→the crusher→the molding rate detection unit→the secondary screening mechanism→the aggregate storage warehouse.

[0074] The return material path is: oversized aggregate from the warehouse belt coarse screening mechanism→the return transfer belt→the feed inlet of the crusher.

[0075] The control signal flow is: the crushing value data→the adjustment of the discharge port→the gap between crushing cavities→the screening parameters→the feedback of the cloud platform, forming a closed-loop control chain.

[0076] It can be understood that the non-contact spectral analyzer of the material transfer warehouse realizes real-time non-destructive detection of the compressive strength of raw materials through the symmetrically installed emission end and receiving end, avoids the damage of traditional sampling, and improves the detection efficiency and data reliability.

[0077] The intelligent adjustment device of the discharge port dynamically controls the opening degree of the gate valve based on the Profinet bus, accurately matches the proportion of coarse and fine aggregate, and ensures the stability of the subsequent crushing and screening processes.

[0078] The 20mm screen hole and the 45° buffer baffle of the warehouse belt coarse screening mechanism accurately separate oversized aggregate (>20mm), the buffer baffle reduces the impact of returned material, and prolongs the service life of the equipment.

[0079] The corrugated pipe soft connection of the transfer warehouse control unit avoids material accumulation and blockage, ensures continuous and uniform feeding, and improves the crushing efficiency.

[0080] The three-cavity ±0.5mm gap adjustment of the crusher independently controls the crushing strength of each cavity through a hydraulic connecting rod, optimizes the uniformity of particle size, and reduces the phenomenon of over-crushing.

[0081] The laser scanner detects at a rate of 2000 frames per second, high-frequency scanning combined with vertical installation design, real-time capture of particle size distribution, and improved molding rate feedback accuracy.

[0082] The secondary screen is continuously adjustable from 0.5mm to 10mm, which is suitable for different grading requirements (such as continuous grading and intermittent grading), and enhances the flexibility of products.

[0083] Modbus protocol linkage of intelligent control center, realize full-process parameter closed-loop control, reduce manual intervention, and improve production consistency.

[0084] The detection wavelength range of the non-contact spectral analyzer is 400-1000 nm, and the detection data is transmitted to the controller in real time through the Profinet bus.

[0085] It can be understood that the 400-1000nm spectral detection covers the characteristic wavelength of common sand and stone minerals, improves the detection accuracy of the crushing value, and reduces the environmental light interference.

[0086] Profinet bus transmission ensures data real-time and anti-interference ability, avoiding traditional analog signal delay or distortion.

[0087] The return material transfer belt and the main production line are arranged in an L shape, and the inclination angle of the buffer baffle is 45°, and the surface is covered with a polyurethane wear-resistant layer.

[0088] It can be understood that the L-shaped layout and the polyurethane baffle save space in compact design, and the polyurethane wear-resistant layer reduces material impact wear and reduces maintenance frequency.

[0089] The servo motor II is connected with the adjusting bolt of the crusher three cavities through a hydraulic connecting rod, and the gap between the middle cavities is dynamically adjusted according to the crushing value data according to the formula. Figure 2

[0090] It can be understood that the servo motor II is connected with the hydraulic connecting rod to realize high-precision (±0.5mm) gap adjustment, ensuring the dynamic balance of crushing strength and discharge particle size.

[0091] The laser scanner has a built-in image recognition algorithm, including the following steps,

[0092] The image of the aggregate is grayed;

[0093] The particle size profile is extracted by edge detection algorithm;

[0094] The qualified rate is calculated and a feedback signal is generated to the PLC controller.

[0095] It can be understood that the image gray scale and edge detection algorithm accurately extract the aggregate profile, with a qualified rate error of less than 1%, and improve the reliability of feedback control.

[0096] The stroke of the pneumatic push rod is 50-100mm, the thrust is 200N, and the vibration frequency of the multi-layer fine screen mesh vibrator is matched with the rotation speed of the crusher discharge belt through the frequency converter.

[0097] ​It can be understood that the pneumatic push rod 200N thrust and 50-100mm stroke ensure that the screen size is quickly and accurately adjusted, the vibration frequency is matched synchronously to avoid material accumulation, and the screening efficiency is improved by 20%.

[0098] The data cloud platform is connected with a customer order system through an industrial router, the gradation parameters include a particle size distribution curve of continuous gradation or a particle size threshold value of discontinuous gradation, the platform automatically generates corresponding screen size instructions and sends them to a PLC controller.

[0099] It can be understood that the cloud platform is connected with the order system, the customer gradation requirements (such as the particle size distribution curve) are automatically analyzed, one-key parameter sending is realized, manual configuration errors are reduced, and the response time is shortened to 5 seconds.

[0100] The energy consumption optimization mechanism includes a power sensor and an energy consumption analysis unit, the power sensor monitors the current and voltage of the crusher in real time, the energy consumption analysis unit calculates the optimal running frequency according to the current and voltage of the crusher and the energy consumption of the crusher, and the device is adjusted according to the optimal running frequency. Figure 3 The power sensor monitors the current and voltage of the crusher in real time, and the energy consumption analysis unit calculates the optimal running frequency according to the current and voltage of the crusher and the energy consumption of the crusher.

[0101] It can be understood that the power sensor monitors in real time, accurately collects the energy consumption data of the crusher, provides a basis for the optimization mechanism, and is expected to reduce the unit energy consumption by 10%-15%.

[0102] The variable-frequency feeder of the transfer warehouse control unit is linked with the crusher current sensor signal, when the load of the crusher exceeds 90% of the rated value, the feeding speed is automatically reduced to a preset safety threshold, and the feeding speed V of the variable-frequency feeder and the crusher current I satisfy the formula shown in the formula. Figure 4 The power sensor monitors the current and voltage of the crusher in real time, and the energy consumption analysis unit calculates the optimal running frequency according to the current and voltage of the crusher and the energy consumption of the crusher.

[0103] It can be understood that the feeding speed is linked with the crushing load, and the speed is automatically reduced when the crusher is overloaded, so that the equipment is prevented from being damaged due to overload, and the failure rate is reduced by 30%.

[0104] The screening method of the multi-stage screening device for sand and gravel aggregate treatment provided by the application comprises the following steps,

[0105] In step S1, the raw materials are subjected to non-contact crushing value detection by a non-contact spectral analyzer in the material transfer warehouse, and the detection data are uploaded to a PLC controller in real time.

[0106] In step S2, the controller dynamically adjusts the opening degree according to the crushing value data, the coarse screening mechanism separates the oversized particle size aggregate and returns the material to the crusher, and the controller calculates the opening degree of the discharge port according to the crushing value data, and the formula is as shown in the formula. Figure 5 The power sensor monitors the current and voltage of the crusher in real time, and the energy consumption analysis unit calculates the optimal running frequency according to the current and voltage of the crusher and the energy consumption of the crusher.

[0107] In step S3, the oversized particle size aggregate is returned to the crusher through the return transfer belt, and the return rate is monitored by a flowmeter and fed back to the PLC controller.

[0108] Step S4, the servo motor II adjusts the middle cavity gap according to the crushing value data and the molding rate feedback, and the specific adjustment logic is:

[0109] If the molding rate < 90%, the middle cavity gap is reduced by 2%;

[0110] If the molding rate ≥ 90%, the current gap is maintained;

[0111] Step S5, the pneumatic push rod adjusts the sieve hole size according to the grading parameter issued by the PLC controller, and the sieve holes are distributed in an arithmetic sequence in the continuous grading mode, and the sieve holes are segmented according to the preset threshold in the intermittent grading mode.

[0112] Step S6, the data cloud platform generates a production report containing the grading deviation, energy consumption and qualified rate, and pushes it to the customer terminal through the industrial router.

[0113] It can be understood that the crushing value dynamic adjustment of steps S1-S2 adjusts the process according to the hardness of the raw material, and the grading accuracy is improved to ±0.5%.

[0114] The middle cavity gap optimization logic of step S4 reduces the gap by 2% when the molding rate < 90%, directly improving the crushing qualified rate to more than 95%.

[0115] The grading mode switching of step S5 meets different engineering requirements (such as concrete aggregate vs. roadbed aggregate) through the arithmetic distribution or threshold segmentation of the sieve hole.

[0116] The cloud platform report pushing of step S6 generates a production data report in real time, supports customer remote monitoring and quality traceability, and improves service efficiency.

[0117] The application realizes high precision, low energy consumption and strong adaptability of sand and gravel aggregate grading full process through non-contact detection, intelligent linkage adjustment, institutionalized screening design and data closed-loop control, meets the differentiated engineering requirements, reduces the operation and maintenance cost, and has significant technical advantages and market competition.

[0118] The application achieves the following remarkable effects

[0119] High-precision detection and real-time feedback:

[0120] The non-contact spectral analyzer (400-1000nm wavelength) detects the raw material crushing value in real time, the detection error is <2%, the data is transmitted through the Profinet bus, and the production decision-making time is shortened to within 10 seconds; the laser scanner (2000 frames / second) vertically monitors the aggregate particle size after crushing, and the qualified rate calculation accuracy reaches 99%.

[0121] Intelligent linkage and grading optimization:

[0122] Crusher three cavity gap independent adjustment (± 0.5mm accuracy), middle cavity gap according to the formula shown in the reference dynamic optimization, grading deviation control within ± 0.5%; two screen mesh through pneumatic push rod (50-100mm stroke) to achieve 0.5-10mm screen hole continuous adjustable, support continuous grading, intermittent grading one key switch, switch time <3 minutes. Figure 2

[0123] Energy consumption and efficiency improvement:

[0124] The return rate is reduced by 20%, and the energy consumption of the crusher is reduced by 15% (unit power consumption is reduced to 4.2-4.5 kWh / ton); screen mechanism design combined with automatic cleaning system, maintenance time is reduced by 40%, screen life is extended by 30%.

[0125] Data closed loop and flexible production:

[0126] Data cloud platform and customer order system direct connection, automatic analysis of grading demand and instruction, order response cycle from 24 hours to 1 hour; production report real-time push customer terminal, support quality traceability and process optimization iteration.

[0127] The above description and drawings fully illustrate the embodiments of the present application, so that those skilled in the art can practice them, other embodiments can include structural and other changes, the embodiments only represent possible changes, unless explicitly required, individual components and functions are optional, and the order of operation can be changed, some embodiments parts and features can be included or replaced by other embodiments parts and features, the embodiments of the present application are not limited to the structure described above and shown in the drawings, and various modifications and changes can be made without departing from the scope thereof, the scope of the present application is only limited by the appended claims.​

Claims

1. A multi-stage screening device for sand and gravel aggregate treatment, characterized by, The application relates to a material transfer warehouse, a discharging port intelligent adjusting device, a warehouse-under belt coarse screening mechanism, a crusher, a transfer bin material control unit, a crusher three-cavity gap adjusting mechanism, a forming rate detection unit, a secondary screening mechanism and an intelligent control center. The discharging port intelligent adjusting device comprises an electric gate valve, a servo motor I and a controller which are connected with a flange of a material transfer warehouse discharging port; the controller receives assay data through a Profinet bus and drives the servo motor I to adjust the opening degree of the gate valve to control the coarse and fine aggregate ratio. The warehouse-under belt coarse screening mechanism is arranged directly below the electric gate valve and comprises a first-level vibrating screen with an inclination angle of 15-30 DEG and a return material transfer belt; the first-level vibrating screen has a screen hole diameter of 20 mm; oversized aggregate slides into the return material transfer belt through a chute; the end of the return material transfer belt is connected to a crusher feeding port through a material guide groove, and a buffer baffle is arranged in the material guide groove. The secondary screening mechanism comprises a plurality of layers of fine screen meshes, a screen box, a vibration frequency adjustable vibrator and a pneumatic push rod; the plurality of layers of fine screen meshes are connected with the screen box through hinges; the screen hole size is continuously adjusted in the range of 0.5 mm to 10 mm through the pneumatic push rod. The material transfer warehouse is internally provided with a crushing value assay mechanism; the crushing value assay mechanism comprises a non-contact spectral analyzer; the emitting end and the receiving end of the non-contact spectral analyzer are arranged at symmetrical positions of the inner wall of the material transfer warehouse and are used for detecting the raw material compression strength in real time and generating assay data; the detection wavelength range of the non-contact spectral analyzer is 400-1000 nm; and the detection data is transmitted to the controller in real time through a Profinet bus. The transfer bin material control unit comprises a transfer bin, a material level sensor and a variable frequency feeder; the bottom of the transfer bin is connected with the variable frequency feeder through a corrugated pipe soft connection; and the variable frequency feeder discharging port is connected to the crusher feeding port through a sealed chute. The crusher three-cavity gap adjusting mechanism comprises an upper cavity, a middle cavity and a lower cavity; the cavity gaps are independently adjusted through a servo motor II driving a hydraulic connecting rod; and the adjustment accuracy is + / - 0.5 mm. The forming rate detection unit is installed on an upper support of a crusher discharging belt and comprises a laser scanner; the scanning direction of the laser scanner is perpendicular to the surface of the belt; the scanning frequency is 2000 frames per second; and the detection data is transmitted to the intelligent control center through an optical fiber. The intelligent control center comprises a PLC controller, a data cloud platform and an industrial router; the PLC controller receives the data of all modules through a Modbus protocol and adjusts the opening degree of the electric gate valve, the crusher cavity gap and the screening parameters according to preset rules.

2. The multi-stage screening device for sand and gravel aggregate treatment according to claim 1, characterized in that The return material transfer belt is arranged in an L shape with the main production line; and the inclination angle of the buffer baffle is 45 DEG; and the surface is covered with a polyurethane wear-resistant layer.

3. The multi-stage screening device for sand and gravel aggregates treatment according to claim 2, characterized in that The servo motor II is connected with the adjusting bolts of the crusher three cavities through a hydraulic connecting rod.

4. The multi-stage screening device for sand and gravel aggregates treatment according to claim 3, characterized in that The laser scanner is internally provided with an image recognition algorithm and comprises the following steps: The aggregate image is subjected to grayscale processing; The particle size contour is extracted through an edge detection algorithm; The qualified rate is calculated and a feedback signal is generated to the PLC controller.

5. The multi-stage screening device for sand and gravel aggregate treatment according to claim 1, characterized in that, The pneumatic push rod has a stroke of 50-100mm and a push force of 200N, and the multi-layer fine screen mesh vibrator is matched with the rotation speed of the crusher discharge belt through a frequency converter.

6. The multi-stage screening device for sand and gravel aggregate treatment according to claim 1, characterized in that, The data cloud platform is connected with the customer order system through an industrial router, the gradation parameters include the particle size distribution curve of continuous gradation or the particle size threshold value of discontinuous gradation, the platform automatically generates corresponding screen hole size instructions and sends them to the PLC controller.

7. The multi-stage screening device for sand and aggregate treatment according to claim 1, characterized in that, The energy consumption optimization mechanism includes a power sensor and an energy consumption analysis unit, and the power sensor monitors the current and voltage of the crusher in real time.

8. The multi-stage screening apparatus for sand and gravel aggregates treatment according to claim 1, characterized in that, The frequency conversion feeder of the transfer warehouse control unit is linked with the current sensor signal of the crusher, and when the load of the crusher exceeds 90% of the rated value, the feeding speed is automatically reduced to a preset safety threshold.

9. A screening method using the multi-stage screening apparatus for sand and gravel aggregates according to any one of claims 1 to 8, characterized by, The method comprises the following steps, In step S1, the raw materials are subjected to non-contact crushing value detection by a non-contact spectral analyzer in the material transfer warehouse, and the detection data are uploaded to the PLC controller in real time; In step S2, the controller dynamically adjusts the opening degree according to the crushing value data, the coarse screen mechanism separates the oversize aggregate and returns it to the crusher; In step S3, the oversize aggregate is returned to the crusher through the return transfer belt, and the return rate is monitored by a flowmeter and fed back to the PLC controller in real time; In step S4, the servo motor II adjusts the middle cavity gap according to the crushing value data and the molding rate feedback, and the specific adjustment logic is as follows: If the molding rate is less than 90%, the middle cavity gap is reduced by 2%; If the molding rate is greater than or equal to 90%, the current gap is maintained; In step S5, the pneumatic push rod adjusts the screen hole size according to the gradation parameters sent by the PLC controller, and in the continuous gradation mode, the screen holes are distributed in an arithmetic sequence, and in the discontinuous gradation mode, the screen holes are segmented according to the preset threshold value; In step S6, the data cloud platform generates a production report containing the gradation deviation, energy consumption and qualified rate, and pushes it to the customer terminal through the industrial router.

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