A control method, device and system for an air separator

Abstract

The application provides a control method of an air separator, comprising the following steps: obtaining a material image on a feeding conveyor belt; determining a material volume flow and a material size according to the material image; determining a target opening size of an air separator adjusting valve according to the material volume flow; determining a target air speed level of the air separator according to the material size; determining a target air volume according to the target opening size of the air separator adjusting valve and the target air speed level; and controlling a fan rotating speed to work at a target rotating speed according to the target air volume. The method can realize work adjustment in the mode of the equipment, and achieves the purposes of accurate material separation and real-time processing capacity.

Description

Technical Field

[0001] This invention relates to the field of material separation using airflow, and specifically to a control method, device, and system for an air classifier. Background Technology

[0002] Air separators are widely used in various waste sorting industries, such as construction waste, organic waste, household waste, and aged waste. The lightest materials they separate include: rags, shredded paper, plastic film, biomass with low moisture content, and wood materials; the heaviest materials include: metals and sand / gravel. These types of waste are usually quite complex, with highly variable compositions, and existing air separators face several inconveniences in processing them.

[0003] 1. When the air classifier is in operation, the nozzle wind speed adjustment and other operations are usually done manually, which is labor-intensive and has low precision.

[0004] 2. Control points such as fans and regulating valves cannot be processed and adjusted according to the real-time processing flow of the air separator;

[0005] 3. Adjusting parameters for different materials requires constant trial and error, and repeated adjustments are inefficient. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a control method, device and system for an air separator, which solves the problems of the prior art that cannot accurately separate materials and cannot adjust control parameters in real time according to the processing flow rate.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0008] A control method for an air classifier includes:

[0009] Acquire images of the materials on the feed conveyor belt;

[0010] Based on the material image, determine the material volumetric flow rate and material size;

[0011] Determine the target opening size of the air classifier regulating valve based on the material volume flow rate;

[0012] Determine the target wind speed level of the air classifier based on the material size;

[0013] The target air volume is determined based on the target opening size and target wind speed level of the air separator regulating valve;

[0014] The fan speed is controlled according to the target air volume to operate at the target speed.

[0015] Optionally, acquiring the image of the material on the feed conveyor belt includes:

[0016] Material images are acquired by a vision sensor positioned above the feed conveyor belt of the air classifier.

[0017] Optionally, determining the material volumetric flow rate based on the material image includes:

[0018] Identify the predefined rectangular area containing the target material in the material image of the feed conveyor belt;

[0019] The target material volume is determined based on the preset rectangular region, the material layer thickness of the preset rectangular region, and the sampling density of the preset rectangular region;

[0020] The volumetric flow rate of the material is obtained based on the target material volume and the belt speed of the feed conveyor.

[0021] Optionally, the target opening size of the air classifier regulating valve is determined based on the material volumetric flow rate, including:

[0022] Based on the correspondence between the material volumetric flow rate and the opening size of the regulating valve, determine the target opening size of the air classifier regulating valve corresponding to the current material volumetric flow rate; wherein, the air classifier regulating valve includes a nozzle regulating valve and / or an air inlet regulating valve.

[0023] Optionally, determining the target wind speed level of the air classifier based on the material size includes:

[0024] Based on the correspondence between material size and the wind speed level of the air classifier, determine the target wind speed level of the air classifier corresponding to the current material size.

[0025] Optionally, determining the target air volume based on the target opening size and target wind speed level of the air separator regulating valve includes:

[0026] The material separation speed is obtained based on the material size;

[0027] Then, based on the obtained material separation speed and the target opening size of the air classifier regulating valve corresponding to the current material volume flow rate, the target air volume is determined.

[0028] A control device for an air separator, comprising:

[0029] The acquisition module is used to acquire images of the materials on the feeding conveyor belt;

[0030] The control module is used to determine the material volumetric flow rate and material size based on the material image; determine the target opening size of the air classifier regulating valve based on the material volumetric flow rate; determine the target wind speed level of the air classifier based on the material size; determine the target air volume based on the target opening size and target wind speed level of the air classifier regulating valve; and control the fan speed to operate at the target speed based on the target air volume.

[0031] A control system for an air separator includes:

[0032] A vision sensor is installed on the feed conveyor belt of the air classifier; and the control device for the air classifier as described above.

[0033] Optionally, the air separator includes:

[0034] Air supply module;

[0035] The air duct module and the filter module are respectively connected to the air supply module;

[0036] The feeding module is connected to the air duct module;

[0037] The separation module is connected to the feeding module;

[0038] The settling module connected to the separation module;

[0039] A return air duct connected to the settling module, which is connected to the air supply module, enables circulating air.

[0040] The feeding module is equipped with a feeding conveyor belt, and the settling module is equipped with a discharging conveyor belt to output light materials.

[0041] The above-described solution of the present invention has at least the following beneficial effects:

[0042] This invention provides a control method for an air classifier, comprising: acquiring an image of material on a feed conveyor belt; determining the material volumetric flow rate and material size based on the material image; determining the target opening size of the air classifier's regulating valve based on the material volumetric flow rate; determining the target wind speed level of the air classifier based on the material size; determining the target air volume based on the target opening size of the air classifier's regulating valve and the target wind speed level; and controlling the fan speed according to the target air volume to operate at the target speed. By using equipment for operational adjustment, the method achieves precise material separation and allows for adjustment of control parameters based on flow rate. Attached Figure Description

[0043] Figure 1 This is a flowchart of the air separator control method provided in an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of an air separator device provided in an embodiment of the present invention;

[0045] Figure 3 This is a cross-sectional schematic diagram of the air separator device provided in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the air separator control method provided in an embodiment of the present invention;

[0047] Figure 5 This is a structural diagram of the air separator control device provided in an embodiment of the present invention;

[0048] Explanation of reference numerals in the attached figures:

[0049] 1. Filter module; 2. Air supply module; 3. Air duct module; 4. Feeding module; 5. Heavy material outlet; 6. Separation module; 7. Sedimentation module; 8. Return air duct; 9. Discharge module; 10. Air inlet regulating valve; 11. Nozzle regulating valve; 12. Vision sensor. Detailed Implementation

[0050] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0051] like Figure 1 As shown, an embodiment of the present invention proposes a control method for an air classifier, comprising:

[0052] Step 11: Obtain an image of the material on the feed conveyor belt;

[0053] Step 12: Determine the material volumetric flow rate and material size based on the material image;

[0054] Step 13: Determine the target opening size of the air classifier regulating valve based on the material volumetric flow rate;

[0055] Step 14: Determine the target wind speed level of the air classifier based on the material size;

[0056] Step 15: Determine the target air volume based on the target opening size and target wind speed level of the air separator regulating valve;

[0057] Step 16: Control the fan speed according to the target air volume and operate at the target speed.

[0058] In an optional embodiment of the present invention, step 11 may include:

[0059] Step 111: Obtain material images using a vision sensor positioned above the feed conveyor belt of the air classifier.

[0060] In this embodiment, a vision sensor is installed above the feeding conveyor belt to collect images of the material on the feeding conveyor belt. Based on the obtained material images and the conveying speed of the feeding conveyor belt, the volumetric flow rate of the material can be calculated in real time, and the size information of the material can be calculated within a certain period.

[0061] In an optional embodiment of the present invention, determining the material volumetric flow rate based on the material image includes:

[0062] Identify the predefined rectangular area containing the target material in the material image of the feed conveyor belt;

[0063] The target material volume is determined based on the preset rectangular region, the material layer thickness of the preset rectangular region, and the sampling density of the preset rectangular region;

[0064] The volumetric flow rate of the material is obtained based on the target material volume and the belt speed of the feed conveyor.

[0065] In this embodiment, the feeding conveyor belt is driven by a variable frequency motor. The material is fed in by the feeding conveyor belt. During the material conveying process, the vision sensor above collects material images in real time. After image processing, the rectangular area material image of the set length (the conveying length in the belt length direction, for example, 1.5m) * set width (the conveying width in the belt width direction, with the belt sidewall as the boundary) is extracted. According to the set sampling density, the material layer thickness at the sampling points is measured to determine the volume within the corresponding range.

[0066] It should be noted that the volumetric flow rate varies due to the different thicknesses of the material layer at the sampling points.

[0067] Taking a unit length (e.g., 1m) outward from the feed inlet along the length of the sampling point range, multiplying this volume by the belt speed gives the volumetric flow rate entering the separation zone at the next moment. This flow rate is calculated in real time, both to obtain the overall processing capacity of the air separator through time accumulation, and to adjust the belt speed of the feed conveyor to reduce flow fluctuations and stabilize the operating conditions of subsequent functional structures.

[0068] In an optional embodiment of the present invention, step 13 may include:

[0069] Step 131: Determine the target opening size of the air classifier regulating valve corresponding to the current material volume flow rate based on the correspondence between the material volume flow rate and the regulating valve opening size; wherein, the air classifier regulating valve includes a nozzle regulating valve and / or an air inlet regulating valve.

[0070] In an optional embodiment of the present invention, step 14 may include:

[0071] Step 141: Determine the target wind speed level of the air classifier corresponding to the current material size based on the correspondence between material size and wind speed level of the air classifier.

[0072] In this embodiment, during the dimensional statistics process, edge detection technology is mainly used to extract the edges of different types of materials. Then, the projected length of the contour is compared with the length and width of the image by pixels to obtain the actual size. The material size statistics only include the material length. The statistical results are graded according to the median size. For example, they are divided into four levels: 25-50mm, 50-100mm, 100-200mm, and 200-400mm. If the median statistical value is 150mm, it corresponds to the 100-200mm level. The size statistics and grading calculation are periodically verified and can be set according to the changes in material size, such as by week or shift.

[0073] In an optional embodiment of the present invention, step 15 may include:

[0074] Step 151: Obtain the material separation speed based on the material size;

[0075] Step 152: Based on the obtained material separation speed and the target opening size of the air separator regulating valve corresponding to the current material volume flow rate, determine the target air volume.

[0076] The present invention also provides a control device 50 for an air classifier, comprising:

[0077] Acquisition module 51 is used to acquire images of materials on the feeding conveyor belt;

[0078] The control module 52 is used to determine the material volumetric flow rate and material size based on the material image; determine the target opening size of the air classifier regulating valve based on the material volumetric flow rate; determine the target wind speed level of the air classifier based on the material size; determine the target air volume based on the target opening size and target wind speed level of the air classifier regulating valve; and control the fan speed to operate at the target speed based on the target air volume.

[0079] In this embodiment, a programmable logic controller (PLC) is used for operation. An acquisition module obtains images of the material on the feeding conveyor belt, and an image processing module calculates the material volumetric flow rate in real time and periodically calculates the material's size information. The material volumetric flow rate information is fed to the PLC, which uses a PID algorithm module to control the feeding belt in real time. The aim is to stabilize the input flow rate, reduce flow fluctuations, establish a relatively stable operating condition, enable steady-state system operation, and reduce system adjustment requirements. The PLC selects the nozzle regulating valve opening size based on the material volumetric flow rate and controls the electric actuator to adjust the regulating valve to the designated position.

[0080] Specifically, the control valve is operated by an electric actuator, which has a position sensor and a self-locking function. It can adjust the opening of the control valve according to the position requirements given by the PLC. At the same time, the self-locking function ensures that the control valve can be stably maintained without continuous power supply.

[0081] The image processing module calculates material size information based on the material image, classifies it, and sends the corresponding size level to the PLC. The PLC presets the speed level based on the size level, calculates the required airflow based on the regulating valve opening size, selects the fan operating point, and sends the fan speed requirement to the fan frequency converter. The fan operating point is selected based on the fan's performance curve at different speeds, prioritizing the highest efficiency point, and preset to the PLC. The overall system control logic achieves "material flow rate determines nozzle size, material size determines airflow range, and fan efficiency optimizes speed," ultimately achieving the goal of efficient material sorting and energy-saving operation.

[0082] During this process, the optimal separation speed varies depending on the particle size of the material. Therefore, after determining the particle size, the separation speed is selected based on empirical values.

[0083] The nozzle opening size is then determined based on the volumetric flow rate. For example, if it is opened to 60%, the opening area can be obtained by combining this opening size with the duct width. Since these data are related to the structure, the opening size is obtained by the position parameters of the push rod or the position requirements given by the PLC. The position parameters of the push rod have a fixed parameter table.

[0084] Based on the separation speed and the opening area, the required air volume can be obtained.

[0085] The present invention also provides a control system for an air separator, comprising:

[0086] A vision sensor is installed on the feed conveyor belt of the air classifier; and the control device for the air classifier as described above.

[0087] In an optional embodiment of the present invention, the air separator includes:

[0088] Air supply module 2;

[0089] The air duct module 3 and the filter module 1 are respectively connected to the air supply module 2;

[0090] The feeding module 4 is connected to the air duct module 3;

[0091] Separation module 6 is connected to the feeding module 4;

[0092] The settling module 7 is connected to the separation module 6;

[0093] The return air duct 8 is connected to the settling module 7 and is connected to the air supply module 2 to realize circulating air;

[0094] The feeding module 4 is equipped with a feeding conveyor belt, and the settling module 7 is equipped with a discharge conveyor belt to output light materials.

[0095] Specifically, an air classifier mainly consists of the following parts:

[0096] Feeding module 4:

[0097] It includes a feed chute and a feed conveyor belt, wherein the belt speed of the feed belt is adjustable to control the amount of material input;

[0098] The feed belt is equipped with a vision sensor 12 and an image analysis module.

[0099] Air supply module 2:

[0100] Includes fans and ducts; the fan motor is controlled by a frequency converter, which can control the air intake volume.

[0101] Air duct module 3:

[0102] It includes air ducts and nozzles. The air inlet of the air duct and the nozzle are equipped with regulating valves, which can control the output air volume, wind speed and wind direction of the spray gun.

[0103] The air inlet regulating valve 10 is mainly used to adjust the ratio of air blowing and air suction by the fan.

[0104] The nozzle regulating valve 11 is mainly used to adjust the nozzle size.

[0105] Separate module 6:

[0106] Includes a separation box, a separation drum, and a process that uses wind power to separate light and heavy materials;

[0107] Heavy material export 5:

[0108] Including heavy material sluices;

[0109] Settlement Module 7:

[0110] Including the expansion tank, which is the part where light materials are separated from the material, detached from the air, and settled onto the discharge conveyor belt;

[0111] Discharge conveyor belt:

[0112] The discharge conveyor belt is the main structure for outputting the light materials separated by wind.

[0113] Return air duct 8:

[0114] The air inlet of the return air duct 8 is connected to the expansion box to draw gas out of the expansion box and achieve a negative pressure state for the equipment. The air outlet is connected to the air inlet of the fan to realize the circulating air system.

[0115] Filtering Module 1:

[0116] It includes filters and their ducts to filter and clean excess gas emitted into the atmosphere. A portion of the airflow from the fan is blown into the filter through the duct regulating valve and then discharged into the atmosphere after filtration.

[0117] In this embodiment, the performance of the fan is typically represented by a set of curves. Operating near the high-efficiency point results in greater energy savings. Therefore, after determining the air volume demand range, selecting the operating point near the high efficiency point based on the fan's inherent characteristics and optimizing the motor speed will bring better energy-saving effects to the system. Thus, this solution presets the relevant high-efficiency points into the PLC parameters for different control modes.

[0118] In the fan, some air will also be discharged into the dust filter; about 60-70% of the airflow is sent to the air nozzle in front of the separation drum and returns to the separation box. The inlet regulating valve is used to regulate the proportion of airflow entering the separation box to ensure the settling effect in the settling chamber. The opening of the regulating valve is determined by the size classification result. The larger the size, the higher the air intake ratio, and the smaller the size, the lower the air intake ratio. The specific value is preset into the PLC after confirmation by test data.

[0119] Compared with the prior art, the present invention has the following beneficial effects:

[0120] Using vision sensors for volumetric flow measurement is directly related to the operating characteristics and requirements of the equipment. The sorting process is related to the volume, shape, size, and density of the material, making it more suitable for operational control. Using weighing or other sensors, however, is limited by the significant differences in material density, and the direct acquisition of volume and size parameters is not precise enough, making accurate control difficult.

[0121] By employing a limited sampling method using visual sensors, hardware computing power requirements are reduced, while real-time accuracy and speed are improved.

[0122] A feed flow control method based on sensor volume measurement;

[0123] A statistical method for processing volume based on sensor volume measurement;

[0124] Image-based statistical measurement method for material dimensions;

[0125] Control logic and method of air separation adjustment mechanism based on volumetric flow rate and material statistical dimensions;

[0126] The air separator employing the above technology uses a self-locking electric push rod equipped with a position sensor as the actuator for regulating the opening of the regulating valve;

[0127] Based on this technology, the air separator can collect operating data, continuously enrich and optimize the control mode library, and realize the data-driven accumulation of operating experience.

[0128] When operating an air classifier, nozzle speed adjustment is usually done manually, which is labor-intensive and has low precision. Using an electric push rod can greatly improve adjustment efficiency and reduce the labor intensity of workers.

[0129] Existing equipment cannot process and adjust relevant control points, such as fans and regulating valves, according to the real-time processing flow of the air separator; this control method can provide more scientific, real-time, and online adjustment.

[0130] Adjusting parameters for different materials requires constant trial and error, which is inefficient; automatic adjustment is convenient and efficient.

[0131] Using this technology, the direct control target and the controlled object can be parameterized, enabling rapid optimization of efficient and energy-saving operation control schemes.

[0132] Based on this control method, the motor will operate stably in the high-efficiency range, which is relatively energy-saving.

[0133] This method provides accurate processing data based on volumetric flow rate, solving the previous problem of not being able to obtain processing volume.

[0134] Electric linear actuators can be used in other ways, such as cylinders, swing cylinders, electric rotary valves, etc.

[0135] The functions of a PLC controller can also be integrated into the image control module or into the DCS or computer host program. The PLC is not necessary; it is just a typical industrial equipment control module.

[0136] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control method of an air separator, characterized by, The method comprises the following steps: acquiring an image of the material on the feeding belt; determining the volume flow and the size of the material according to the image of the material; determining the target opening size of the air separator adjusting valve according to the volume flow of the material; determining the target air speed level of the air separator according to the size of the material; determining the target air volume according to the target opening size of the air separator adjusting valve and the target air speed level; controlling the fan to work at the target speed according to the target air volume; wherein, determining the size of the material according to the image of the material comprises: obtaining the size information of the material according to the image of the material and the conveying speed of the feeding belt; wherein, determining the volume flow of the material according to the image of the material comprises: determining a preset rectangular area of the target material in the image of the material on the feeding belt, and extracting a rectangular area image of the material with a preset length and a preset width through image processing; wherein, the preset length is the conveying length in the belt length direction, and the preset width is the conveying width with the belt edge as the boundary in the belt width direction; determining the volume of the target material according to the preset rectangular area, the layer thickness of the preset rectangular area, and the sampling density of the preset rectangular area; obtaining the volume flow of the material according to the volume of the target material and the belt speed of the feeding belt; wherein, determining the target opening size of the air separator adjusting valve according to the volume flow of the material comprises: determining the target opening size of the air separator adjusting valve corresponding to the current volume flow of the material according to the corresponding relationship between the volume flow of the material and the opening size of the adjusting valve; wherein, the air separator adjusting valve comprises a nozzle adjusting valve and / or an air inlet adjusting valve; wherein, determining the target air speed level of the air separator according to the size of the material comprises: determining the target air speed level of the air separator corresponding to the current size of the material according to the corresponding relationship between the size of the material and the air speed level of the air separator; when the size of the material is counted, the edge detection technology is used to extract the edges of different kinds of materials, the actual size of the material is obtained by comparing the projection length of the material profile with the length and width of the image in pixels, and the size of the material is counted only in the length, and the statistical result is classified according to the median corresponding size.

2. The control method of a winnower according to claim 1, characterized in that, The method comprises the following steps: acquiring an image of the material on the feeding belt; 3. The control method of a winnower according to claim 1, characterized in that, controlling the fan to work at the target speed according to the target air volume; wherein, determining the size of the material according to the image of the material comprises: obtaining the size information of the material according to the image of the material and the conveying speed of the feeding belt; 4. A control device for an air separator, characterized in that wherein, determining the volume flow of the material according to the image of the material comprises: determining a preset rectangular area of the target material in the image of the material on the feeding belt, and extracting a rectangular area image of the material with a preset length and a preset width through image processing; wherein, the preset length is the conveying length in the belt length direction, and the preset width is the conveying width with the belt edge as the boundary in the belt width direction; determining the volume of the target material according to the preset rectangular area, the layer thickness of the preset rectangular area, and the sampling density of the preset rectangular area; obtaining the volume flow of the material according to the volume of the target material and the belt speed of the feeding belt; wherein, determining the target opening size of the air separator adjusting valve according to the volume flow of the material comprises: determining the target opening size of the air separator adjusting valve corresponding to the current volume flow of the material according to the corresponding relationship between the volume flow of the material and the opening size of the adjusting valve; wherein, the air separator adjusting valve comprises a nozzle adjusting valve and / or an air inlet adjusting valve; wherein, determining the target air speed level of the air separator according to the size of the material comprises: determining the target air speed level of the air separator corresponding to the current size of the material according to the corresponding relationship between the size of the material and the air speed level of the air separator; when the size of the material is counted, the edge detection technology is used to extract the edges of different kinds of materials, the actual size of the material is obtained by comparing the projection length of the material profile with the length and width of the image in pixels, and the size of the material is counted only in the length, and the statistical result is classified according to the median corresponding size. The method comprises the following steps: acquiring an image of the material on the feeding belt; controlling the fan to work at the target speed according to the target air volume; wherein, determining the size of the material according to the image of the material comprises: According to the material image, the size information of the material is obtained in combination with the feeding belt conveying speed; The method comprises the following steps: A preset rectangular area of the target material in the material image of the feeding belt is determined, and a rectangular area material image of a preset length multiplied by a preset width is extracted through image processing; wherein the preset length is the conveying length in the belt length direction, and the preset width is the conveying width with the belt baffle as the boundary in the belt width direction; The target material volume is determined according to the preset rectangular area, the layer thickness of the preset rectangular area, and the sampling density of the preset rectangular area; The material volume flow is obtained according to the target material volume and the belt speed of the feeding belt; The target opening size of the air separator adjusting valve is determined according to the material volume flow, and the method comprises the following steps: The target opening size of the air separator adjusting valve corresponding to the current material volume flow is determined according to the corresponding relationship between the material volume flow and the opening size of the adjusting valve; wherein the air separator adjusting valve comprises a nozzle adjusting valve and / or an air inlet adjusting valve; The target air speed level of the air separator is determined according to the material size, and the method comprises the following steps: The target air speed level of the air separator corresponding to the current material size is determined according to the corresponding relationship between the material size and the air speed level of the air separator; when the material size is counted, the edge detection technology is used to extract the edges of different kinds of materials, the actual material size is obtained by comparing the material profile projection length with the image length and width in pixels, and the material size counting only counts the material length, and the counting result is classified according to the median corresponding size.

5. A control system for an air separator, characterized in that The method comprises the following steps: A visual sensor is arranged on the feeding belt of the air separator; The control device of the air separator according to claim 4.

6. A control system for a winnower as claimed in claim 5, characterised in that, The air separator comprises: A wind supply module (2); A wind channel module (3) and a filter module (1) connected with the wind supply module (2) respectively; A feeding module (4) connected with the wind channel module (3); A separation module (6) connected with the feeding module (4); A sedimentation module (7) connected with the separation module (6); A return air duct (8) connected with the sedimentation module (7), wherein the return air duct (8) is connected with the wind supply module (2) to realize circulating air; The feeding belt is arranged in the feeding module (4), and the discharge belt is arranged in the sedimentation module (7) to output light substances.

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