Material conveying control method, electronic equipment and material conveying system

Abstract

The present invention belongs to the field of industrial control technology and discloses a material conveying control method, electronic equipment, and material conveying system. The material conveying control method includes: calculating a first speed of a servo motor according to a given material discharge speed, the volume of a material distribution trough in a material distribution device, the number of material distribution troughs in the material distribution device, and the material density; during material conveying, measuring a first weight of a metering silo in real time, calculating an actual material discharge weight and an actual material discharge speed according to the first weight and a second weight at a preset historical moment; calculating a theoretical material discharge weight based on a given material discharge speed and a time difference between the current moment and a preset historical moment; when the difference between the actual material discharge weight and the theoretical material discharge weight exceeds a preset range, determining a second speed of the servo motor according to the actual material discharge speed, the given material discharge speed, and the actual speed of the servo motor until material conveying is completed. This method can improve conveying accuracy and achieve quantitative material delivery.

Description

Technical Field

[0001] The present invention belongs to the technical field of pneumatic material transportation, and in particular relates to a material transportation control method, electronic equipment and a material transportation system. Background Art

[0002] Currently, pneumatic conveying technology is primarily used to feed powders or granules. This technology uses a dispensing device (such as a rotary dispensing valve or screw conveyor) to feed the powder or granules from a metering silo to a pneumatic conveying assembly (such as a pneumatic pipe conveyor). This pneumatic conveying assembly then uses compressed air to transport the powder or granules through a pipeline. This technology is widely used in fields such as chemical engineering, environmental protection, and building materials. The dispensing device provides quantitative feeding, while the metering silo is equipped with a weighing system to measure the weight of material conveyed per unit time.

[0003] However, all material distribution equipment has the following problems: the filling rate problem, that is, the weight of the material falling into the valve groove of the rotary distribution valve or the spiral groove of the screw conveyor (the valve groove and the spiral groove are collectively referred to as the distribution groove) each time is not fixed. Sometimes it is full, and sometimes it is not. This leads to inaccurate material transportation volume per unit time; the gap of the sealing ring of the discharge port is prone to accumulation of material, affecting the transportation accuracy; due to positive pressure transportation, the material is easy to pass through the gap of the distribution equipment at high speed and fall rapidly, affecting the transportation accuracy of the distribution equipment.

[0004] Therefore, during current material transportation, it is difficult for the material separation equipment to quantitatively and accurately transport materials to the pneumatic conveying components, and the conveying accuracy needs to be improved. Summary of the Invention

[0005] The object of the present invention is to provide a material conveying control method, electronic equipment and a material conveying system, which can improve the material conveying accuracy.

[0006] A first aspect of the present invention discloses a material conveying control method, comprising:

[0007] Calculating a first rotational speed of a servo motor according to a given material discharge speed, a volume of a material trough in the material distributing device, a number of material troughs in the material distributing device, and a material density, wherein the servo motor is used to drive the material distributing device to rotate, and the material distributing device is provided with a plurality of material distributing troughs along a circumferential direction;

[0008] During the material conveying process, the first weight of the metering silo is measured in real time, and the actual unloading weight and the actual unloading speed are calculated based on the first weight and the second weight at a preset historical moment; the theoretical unloading weight is calculated based on a given unloading speed and the time difference between the current moment and the preset historical moment; when the difference between the actual unloading weight and the theoretical unloading weight exceeds a preset range, the second speed of the servo motor is determined based on the actual unloading speed, the given unloading speed and the actual speed of the servo motor until the material conveying is completed.

[0009] In some embodiments, the material dispensing device is a rotary dispensing valve, the valve core of the rotary dispensing valve has valve teeth, and two adjacent valve teeth form the dispensing trough. The material conveying process also includes:

[0010] Calculate the unloading time of the material distribution chute according to the tooth height of the valve teeth;

[0011] Calculate the maximum speed of the servo motor according to the unloading time and the angle of the feed chute in the circumferential direction;

[0012] When the first speed or the second speed exceeds the maximum speed, a warning signal is sent.

[0013] In some embodiments, determining the second speed of the servo motor according to the actual material feeding speed, the given material feeding speed, and the actual speed of the servo motor includes:

[0014] Calculating the ratio of the given material feeding speed to the actual material feeding speed;

[0015] The product of the ratio and the actual rotational speed is calculated to obtain the second rotational speed.

[0016] In some embodiments, the dispensing equipment is a rotary dispensing valve, which has a valve core and a shell, and there is a gap between the valve core and the inner wall of the shell. When the rotary dispensing valve rotates, air is blown to the discharge port of the metering silo through the first air supply valve, so that the material accumulated in the gap is blown back to the discharge port, and the material at the discharge port is broken, and / or, air is blown to the discharge port of the metering silo through the second air supply valve to break the arch of the material at the discharge port. The blowing direction of the second air supply valve and the blowing direction of the first air supply valve are staggered.

[0017] In some embodiments, the valve core is provided with valve teeth, and when the rotary dispensing valve rotates, the scraper plates on the valve teeth are used to scrape away the material accumulated in the gap.

[0018] A second aspect of the present invention discloses a material conveying system, comprising:

[0019] A metering silo, a weighing device, a material distribution equipment, a pneumatic conveying component, a control device, a servo motor, and a receiving silo. The metering silo is used for temporarily storing materials, the weighing device is used to weigh the materials in the metering silo, the feed inlet of the material distribution equipment is connected to the metering silo, the feed outlet of the material distribution equipment is connected to the pneumatic conveying component, the feed outlet of the pneumatic conveying component is connected to the receiving silo, the servo motor is electrically connected to the material distribution equipment, the control device is electrically connected to the servo motor, and any one of the above-mentioned material conveying control methods is running on the control device.

[0020] In some embodiments, it also includes a frame and a conveying pipeline, the discharge port of the pneumatic conveying component is connected to a hose, the hose is fixed on the frame, the first end of the conveying pipeline is connected to the hose, and the second end of the conveying pipeline is connected to the receiving silo.

[0021] In some embodiments, the material distribution equipment is a rotary material distribution valve, and the rotary material distribution valve is provided with a first air supply valve and a second air supply valve. The first air supply valve and the second air supply valve are arranged adjacent to the material inlet of the rotary material distribution valve, and the blowing direction of the first air supply valve and the blowing direction of the second air supply valve are staggered.

[0022] In some embodiments, the rotary dispensing valve has a valve core, on which multiple valve teeth are distributed circumferentially, and multiple scraper plates are also provided. The scraper plates are installed on the top of the valve teeth and the multiple scraper plates are distributed at intervals on the multiple valve teeth. The scraper plates are made of flexible material.

[0023] In some embodiments, a baffle plate is installed obliquely in the rotary distributing valve, and the feed port of the rotary distributing valve is divided into a feed chamber and a baffle chamber by the baffle plate. An anti-stuck block is fixed in the baffle chamber, and the anti-stuck block has a plurality of tooth-shaped protrusions, and both sides of the protrusion are inclined surfaces, and the inclined surfaces are arranged obliquely downward from the top of the protrusion to both sides of the protrusion. The bottom of the anti-stuck block is provided with an arc-shaped surface, and the position where the arc-shaped surface intersects with the root of the protrusion is provided with an avoidance portion.

[0024] The beneficial effects of the present invention are:

[0025] The material conveying control method and material conveying system of the present invention compensate for the filling rate of the material distribution equipment by intelligently controlling the rotation speed of the servo motor, accurately control the conveying speed through closed-loop control, correct the error of the conveying weight online, improve the conveying accuracy, and realize the quantitative conveying of materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings herein illustrate specific examples of the technical solutions described in the present invention, and together with the specific implementation methods constitute a part of the specification, and are used to explain the technical solutions, principles and effects of the present invention.

[0027] Unless otherwise specified or defined, the same reference numerals in different drawings represent the same or similar technical features, and the same or similar technical features may also be represented by different reference numerals.

[0028] Figure 1 is a perspective view of a material conveying system disclosed in an embodiment of the present invention;

[0029] Figure 2 It is a three-dimensional diagram of a rotary dispensing valve in a material conveying system;

[0030] Figure 3 It is a cross-sectional view of a rotary dispensing valve in a material conveying system;

[0031] Figure 4 It is a three-dimensional diagram of the anti-jamming block in the material conveying system;

[0032] Figure 5 This is a flow chart of a material conveying control method disclosed in an embodiment of the present invention.

[0033] Description of reference numerals:

[0034] 100, quantitative conveying component, 110, metering silo, 120, weighing device, 130, material distribution equipment, 140, pneumatic conveying component, 150, control device, 160, servo motor, 170, first frame,

[0035] 200, receiving assembly, 210, receiving silo, 220, second rack,

[0036] 300, pipeline,

[0037] 400. Rotary dispensing valve, 410. Valve core, 411. Valve slot, 412. Valve teeth, 420. Housing, 430. First air supply valve, 440. Second air supply valve, 450. Scraper plate, 460. Baffle plate, 470. Feed chamber, 480. Baffle chamber, 490. Anti-stuck block, 491. Protrusion, 492. Arc-shaped surface, 493. Avoidance portion. DETAILED DESCRIPTION

[0038] Unless otherwise specified or defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. In combination with the technical solution of the present invention in a realistic scenario, all technical and scientific terms used herein may also have meanings corresponding to the purpose of implementing the technical solution of the present invention. The "first, second..." used herein is only used to distinguish the names and does not represent a specific quantity or order. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] It should be noted that when an element is considered to be "fixed to" another element, it can be directly fixed to the other element or there can be an intermediate element; when an element is considered to be "connected to" another element, it can be directly connected to the other element or there can be an intermediate element; when an element is considered to be "mounted on" another element, it can be directly mounted on the other element or there can be an intermediate element. When an element is considered to be "located on" another element, it can be directly located on the other element or there can be an intermediate element.

[0040] Unless otherwise specified or defined, the “said” and “the” used in this document refer to the technical features or technical contents mentioned or described before the corresponding position, and the technical features or technical contents may be the same as or similar to the technical features or technical contents mentioned therein. In addition, the terms “including” and “having” and any variations thereof used in this document are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or devices.

[0041] When using pneumatic conveying technology to transport powder or granular materials, although the metering silo is currently weighed at regular intervals, due to the influence of many factors, it is still difficult to achieve quantitative and accurate delivery of materials to the pneumatic conveying components per unit time, and the conveying accuracy still needs to be improved.

[0042] In order to improve the conveying accuracy, the present invention, on the one hand, improves the structure of the existing material conveying system, and on the other hand, adopts closed-loop control during the material conveying process to perform real-time compensation on the servo motor controlling the material distribution equipment, thereby realizing quantitative conveying of materials.

[0043] Specifically, if Figure 1 As shown, this embodiment provides a material conveying system for conveying powdered materials. It includes a quantitative conveying component 100 and a receiving component 200, and the quantitative conveying component 100 and the receiving component 200 are connected by a conveying pipe 300. The quantitative conveying component 100 conveys the material to the receiving component 200 in a quantitative manner within a unit time. The quantitative conveying component 100 mainly includes a metering silo 110, a weighing device 120, a material distribution device 130, a pneumatic conveying component 140, a control device 150 and a servo motor 160. The quantitative conveying component 100 is fixed to the first frame 170; the receiving component 200 mainly includes a receiving silo 210, which is fixed to the second frame 220. The metering silo 110 stores powdered materials, and the bottom of the metering silo 110 is a discharge port, and the top is a feed port. The weighing device 120 is installed on the metering silo 110 to weigh the powdered materials in the metering silo 110. The discharge port of the metering silo 110 is connected to the feed port of the material distribution device 130, and the discharge port of the material distribution device 130 is connected to the pneumatic conveying component 140. The material distribution device 130 is commonly a rotary material distribution valve or a screw conveyor. Figure 2 and Figure 3As shown, this embodiment is a rotary dispensing valve 400, and a plurality of valve slots 411 are distributed circumferentially on the valve core 410 of the rotary dispensing valve 400. When the rotary dispensing valve 400 rotates, the powder in the valve slot 411 is discharged one by one at the outlet of the rotary dispensing valve 400 and conveyed to the inlet of the pneumatic conveying component 140. Each valve slot 411 is a dispensing slot. Similarly, if the dispensing equipment is a screw conveyor, a spiral groove is provided circumferentially on the screw conveyor. Each spiral groove can accommodate powder, and the spiral groove is equivalent to a dispensing slot.

[0044] The discharge port of the pneumatic conveying assembly 140 is connected to the receiving silo 210 through the conveying pipe 300. The servo motor 160 is electrically connected to the material distributing device 130 to control the rotation speed of the material distributing device 130. It is preferred to use a servo motor instead of an ordinary motor to more conveniently achieve closed-loop control of powder material conveying. The control device 150 is electrically connected to the servo motor 160, and an electronic terminal with a touch screen (not shown in the figure) can also be installed on the first frame 170. A given discharge speed can be input through the touch screen, and the various parameters of the equipment in the conveying system can be displayed on the touch screen. The conveying volume can also be graphically displayed, such as a discharge curve chart based on the conveying volume and time. A material conveying control method is run on the control device 150, which sends a control signal to the servo motor 160 based on the relevant parameters input on the touch screen, thereby controlling the position, speed and torque of the material distributing device 130. During the material conveying process, the rotation speed of the servo motor 160 can be controlled in real time, deviations that occur during the conveying process can be corrected in time, and conveying accuracy can be improved.

[0045] Since the pneumatic conveying assembly 140 conveys powder to the receiving silo 210 through the conveying pipe 300, the weight of the material conveyed each time is different due to air pressure or the fact that the fill rate of the feed trough is not 100%. During the conveying process, the conveying pipe 300 will fluctuate, generating a pulling force on the pneumatic conveying assembly 140, dragging the pneumatic conveying assembly 140. The pneumatic conveying assembly 140 is connected to the rotary feed valve 400, and the rotary feed valve 400 is connected to the metering silo 110. Therefore, when the pneumatic conveying assembly 140 is dragged, the metering silo 110 may experience slight vibrations, affecting the accuracy of weighing. To avoid this situation, the present embodiment adds a hose between the pneumatic conveying assembly 140 and the conveying pipe 300. The discharge port of the pneumatic conveying assembly 140 is connected to the hose, the first end of the conveying pipe 300 is connected to the hose, and the second end of the conveying pipe 300 is connected to the receiving silo 210. The hose is fixed to the first frame 170. By docking the conveying pipe 300 with the hose, and fixing the hose on the first frame 170, when the conveying pipe 300 fluctuates, the pulling force is transmitted to the first frame 170, and will not drag on the pneumatic conveying component 140, nor will it affect the weighing accuracy, thereby improving the conveying accuracy by ensuring the measurement accuracy.

[0046] refer to Figure 2 and Figure 3 The rotary dispensing valve 400 comprises a valve core 410 and a housing 420, with a gap between the valve core 410 and the inner wall of the housing 420. Powder may accumulate in these gaps, which may affect the rotation of the rotary dispensing valve 400 and reduce the actual rotation speed. On the other hand, it may also cause the weight of the material discharged by the weighing device to be inconsistent with the weight actually delivered to the pneumatic conveying component. For example, the weight of the material discharged by the weighing device is X kg, but the actual weight delivered to the pneumatic conveying component may be less than X kg, affecting the discharge accuracy. Therefore, in this embodiment, a first air supply valve 430 and a second air supply valve 440 are installed near the feed inlet of the rotary dispensing valve 400. Specifically, there are two first air supply valves 430, installed on the left and right sides of the rotary dispensing valve 400. Of the air flow blown out by the first air supply valve 430, a portion of the air flow blows the material accumulated in the gap back to the discharge port of the metering silo 110, while the other portion of the air flow flows upward, playing a certain role in breaking the arch of the discharge port of the metering silo 110. The second air supply valve 440 is positioned in front of and / or behind the rotary dispensing valve 400. The blowing directions of the first air supply valve 430 and the second air supply valve 440 intersect. The airflow from the second air supply valve 440 enhances the arch-breaking effect, activates the powder, and prevents material accumulation. Therefore, the first and second air supply valves 430 and 440 both provide a seal, preventing material accumulation in the gap to a certain extent, and improve the fill rate of the dispensing trough.

[0047] The first air supply valve 430 and the second air supply valve 440 can blow away the powder near the discharge port of the metering silo 110, but powder may still accumulate in the gap between the valve core 410 and the shell 420 of the rotary dispensing valve 400. Therefore, this embodiment also installs a plurality of scraper plates 450. Specifically, a plurality of valve teeth 412 are distributed circumferentially on the valve core 410, and the scraper plates 450 are installed on the top of the valve teeth 412. Four scraper plates 450 are installed and installed at intervals on the plurality of valve teeth 412. The scraper plates 450 are made of a flexible material, such as a silicone scraper. The height requirement of the scraper plates 450 protruding from the valve teeth 412 meets the following requirements: the gap between the scraper plates 450 and the inner wall of the shell 420 can pass air but not material. By setting up the scraper plate 450, on the one hand, it can play a sealing role to prevent part of the powder from falling quickly through the gap between the valve core 410 and the inner wall of the shell 420 when the powder falls under pressure, and the accuracy of quantitative delivery cannot be guaranteed; on the other hand, it can also play the role of scraping off the powder in the gap to improve the delivery accuracy.

[0048] In this embodiment, only the ends of four valve teeth 412 are embedded with silicone scrapers. Embedding all valve teeth 412 with silicone scrapers is not considered because: if too many valve teeth are equipped with silicone scrapers, the friction of the rotary dispensing valve 400 will increase, affecting the rotation of the rotary dispensing valve 400. Conversely, if too few valve teeth are equipped with silicone scrapers, the sealing and scraping functions will not be achieved. Therefore, the number of scrapers 450 is preferably 3-5.

[0049] In some embodiments, in order to prevent powder leakage and achieve airtightness, sealing rings may be provided at multiple locations on the inner wall of the housing 420 of the rotary dispensing valve 400 to improve the sealing performance of the entire device and prevent material leakage.

[0050] In this embodiment, in order to ensure that the material enters from the side and reduce material accumulation and jamming, a material blocking plate 460 is also installed obliquely in the rotary material dispensing valve 400. The material blocking plate 460 divides the feed port of the rotary material dispensing valve 400 into a feed chamber 470 and a material blocking chamber 480. The material enters the valve slot 411 from the feed chamber 470, thereby improving the slot filling rate. In order to improve the sealing effect of the material blocking chamber 480, an anti-jamming block 490 is fixedly installed in the material blocking chamber 480, such as Figure 4 As shown, the anti-jamming block 490 has multiple tooth-like protrusions 491, with inclined surfaces on both sides, sloping downward from the top of the protrusions 491. The bottom of the anti-jamming block 490 is provided with an arcuate surface 492 corresponding to the running trajectory of the valve teeth 412. The intersection of the arcuate surface 492 and the base of the protrusion 491 is provided with an escape portion 493. In this embodiment, the escape portion 493 is a square groove, but is not limited to this. By setting the material baffle plate 460, the situation of the rotary distributing valve 400 being stuck due to material accumulation can be greatly reduced, thereby improving the slot full rate; by setting an anti-stuck block 490 in the material baffle chamber 480, the two sides of the protrusion 491 are inclined surfaces, and an avoidance portion 493 is provided, so that even if very little material enters the material baffle chamber 480, it can fall along the inclined surface through the avoidance portion 493 into the valve slot 411 of the rotary distributing valve 400, thereby preventing the material from entering the gap between the valve core 410 and the shell 420 from the material baffle chamber 480, thereby achieving a sealing effect, and the material is guided to fall into the valve slot 411, which can improve the slot full rate.

[0051] Therefore, the material conveying system of this embodiment adopts a first air supply valve and a second air supply valve to realize air flow backblowing to break the arch, activate the powder, prevent material accumulation, and achieve the effect of sealing and improving the slot full rate; through the material baffle plate and anti-stuck block, the material discharge path is restricted, which achieves the effect of sealing and improving the slot full rate; and an elastic scraper plate is used to achieve sealing and scrape off the powder in the gap, which achieves the effect of sealing and making the weighing weight and the weight delivered to the pneumatic conveying component as consistent as possible, and by adding a hose to avoid affecting the weighing accuracy, the overall conveying accuracy is improved.

[0052] Since the rotary dispensing valve conveys materials under positive pressure during the conveying process, the material can easily pass through the gap of the dispensing valve at high speed and fall rapidly, affecting the actual speed and conveying accuracy of the rotary dispensing valve; the gap of the sealing ring of the discharge port can easily accumulate material, affecting the falling of the material, resulting in a decrease in the slot fill rate of the rotary dispensing valve (that is, the proportion of powder in the valve slot); moreover, changes in the moisture, temperature, particle size distribution and other characteristics of the powder or granular material may lead to differences in fluidity. For example, moisture absorption and agglomeration of the material may affect the speed of the rotary dispensing valve; loose materials may become compacted due to vibration or changes in air pressure during conveying, resulting in different weights under the same volume. Therefore, the conveying weight of the conveying system is nonlinear and time-varying (such as changes in material characteristics). Traditional PID parameters are difficult to adjust adaptively, and overshoot or steady-state errors are prone to occur.

[0053] To address these situations, it is necessary to implement closed-loop control and adjust the speed of the rotary discharge valve in real time. By adjusting the speed, deviation correction and compensation can be performed to improve the conveying accuracy.

[0054] Therefore, this embodiment also provides a material conveying control method, which runs on a control device in a material conveying system and can control the servo motor connected to the rotary dispensing valve in real time to achieve closed-loop control of material conveying. Figure 5 As shown, the specific steps include:

[0055] Step S100: Calculating a first speed of the servo motor according to a given material feeding speed, a volume of a material feeding trough in the material feeding device, a number of material feeding troughs in the material feeding device, and a material density;

[0056] The dispensing equipment in this embodiment is a rotary dispensing valve. The formula for calculating the discharge weight of the rotary dispensing valve per rotation is: G=Vρa, wherein G is the weight, V is the volume of a dispensing trough in the rotary dispensing valve, ρ is the material density, and a is the number of dispensing troughs in the rotary dispensing valve.

[0057] The calculation formula for the blanking speed is: U=Gn=Vρan; where U is the blanking speed, G is the blanking weight per one rotation of the servo motor, and n is the speed of the servo motor.

[0058] Therefore, after inputting a given feed rate U on the touch screen, the servo motor's speed n can be calculated using the above formula. The driver then uses pulse commands to control the servo motor to operate at the calculated speed n. It should be noted that for ease of understanding, the feed rate calculation formula in this embodiment assumes a transmission ratio of 1 between the servo motor and the rotary feed valve. During use, the corresponding conversion can be performed based on the transmission ratio.

[0059] For example: given a material feeding speed U of 5 kg / hour and a material density ρ of 300 kg / m 3 =0.3g / cm 3The volume of each trough of the rotary dispensing valve is V = 11.9 cm³. The rotary dispensing valve has 14 troughs. The weight of material discharged per rotation of the rotary dispensing valve is G = Vρ = 11.9 x 0.3 = 3.57 g. The angle of each trough is 360 / 14 = 25.7 degrees, meaning the rotary dispensing valve delivers 3.57 g of material for every 25.7 degrees of rotation. The structure of the rotary dispensing valve dictates that material must be fed per trough. Given a discharge rate of 5 kg / hour, the servo motor's first speed, n, is calculated to be [(5000 / 3.57) x 25.7] / 360 = 99.98 rpm, or 1.67 rpm.

[0060] By accurately converting the given feeding speed into the first speed of the servo motor, rather than setting the first speed of the servo motor based on experience, the initial speed of the servo motor is accurate, avoiding material spillage when the speed of the rotary dispensing valve is too high, and avoiding insufficient filling rate and fluctuation of the conveying volume when the speed is too low, which is beneficial to improving the conveying accuracy.

[0061] During the material conveying process, closed-loop control is achieved by executing the following steps:

[0062] Step S200: measuring a first weight of the metering silo in real time, and calculating an actual unloading weight and an actual unloading speed based on the first weight and a second weight at a preset historical moment;

[0063] The weighing system measures the weight of the metering silo over time in real time and calculates the actual discharge weight and discharge rate. Specifically, the actual discharge weight is: g1 - g0, and the actual discharge rate is: u = (g1 - g0) / (t1 - t0), where u is the actual discharge rate, g1 is the first weight of the metering silo at the current moment (i.e., the time of the current measurement), g0 is the second weight of the metering silo at a preset historical moment (i.e., the time of the previous measurement), t1 is the time of the current measurement, and t0 is the time of the previous measurement. It should be noted that the specific time of the preset historical moment is not restricted and can be dynamic, inferred from the measurement time interval. For example, if the current time is 2:00 PM and the measurement time interval is 5 minutes, the preset historical moment is 1:55 PM. It can also be static, such as the start time of a powder conveying task.

[0064] Step S300: Calculating theoretical blanking weight based on a given blanking speed and the time difference between the current moment and a preset historical moment;

[0065] The theoretical material weight is calculated by multiplying the given material delivery speed by the time difference between the current moment and the preset historical moment.

[0066] Step S400: When the difference between the actual material feeding weight and the theoretical material feeding weight exceeds a preset range, a second speed of the servo motor is determined according to the actual material feeding speed, the given material feeding speed and the actual speed of the servo motor.

[0067] The difference between the actual and theoretical material weights is calculated. This difference may be caused by a deviation between the actual and expected speeds, or by a significant difference in material density. When the difference exceeds a preset range (e.g., ±30 grams), correction begins. Correction occurs by accelerating the servo motor (e.g., by 5%) if the actual weight is less than the theoretical weight; and by decelerating the servo motor (e.g., by 5%) if the actual weight is greater than the theoretical weight.

[0068] This embodiment adjusts the speed of the servo motor (i.e., the second speed) based on the ratio of the given feeding speed to the actual feeding speed when a deviation occurs. For example, when the weight deviation is monitored to be greater than ±30g at time point t1, the ratio of the given feeding speed (e.g., 5kg / h) to the actual feeding speed (Xkg / h) is calculated, and the ratio is multiplied by the actual speed n of the servo motor to obtain the second speed of the servo motor, that is, the speed of the servo motor is adjusted to 5000n / X.

[0069] Since excessively high rotation speed of the rotary dispensing valve may cause material to be scattered, this embodiment also calculates the maximum rotation speed of the rotary dispensing valve based on the equipment parameters of the rotary dispensing valve during the material conveying process. When the speed of the servo motor exceeds the maximum rotation speed, an early warning signal is sent and displayed on the touch screen. Specifically, two adjacent valve teeth on the valve core of the rotary dispensing valve form a valve slot, i.e., a dispensing slot. This embodiment calculates the discharge time of the valve slot based on the tooth height of the valve teeth; and then calculates the maximum rotation speed of the servo motor based on the discharge time and the circumferential angle of the valve slot. For example: assuming the tooth height of the rotary dispensing valve is ,according to , then the unloading time is ,in, is the acceleration due to gravity. Angle between the valve slot and the circumference Calculate the time per revolution: , calculate the maximum speed of the servo motor based on the time per revolution. For example: the tooth height is 15mm and the angle is 45 degrees, then , time per revolution: , maximum speed: That is, if the speed of the rotary dispensing valve exceeds 136 rpm, the feeding accuracy will be affected and an alarm signal will be issued.

[0070] In some embodiments, a theoretical unloading curve and an actual unloading curve are plotted with time as the horizontal axis and unloading weight as the vertical axis. The actual unloading curve is plotted based on the actual unloading weight measured at different times in step S200, and the theoretical unloading curve is plotted based on the first speed of the servo motor calculated in step S100 and the unloading weight per revolution of the rotary dispensing valve. For example, if the unloading speed is 5 kg / hour and the unloading weight of the rotary dispensing valve per revolution of the dispensing trough is 3.57 g, the unloading weight per revolution is 3.57×14=49.98 g. ， The first speed of the servo motor is calculated to be 1.67 rpm, and the linear relationship between the theoretical mass delivered by the rotary dispensing valve to the pneumatic conveying component and time can be obtained, that is, the discharge weight per minute is: 1.67×49.98g=83.47g, and the theoretical discharge curve is drawn.

[0071] It is also possible to compare the theoretical feeding curve with the actual feeding curve, and monitor the deviation between the actual feeding curve and the theoretical feeding curve in real time. If the deviation exceeds ±30 grams, correction will be performed.

[0072] In this embodiment, when the rotary dispensing valve rotates, air is also blown to the discharge port of the metering silo through the first air supply valve, so that the material accumulated in the gap between the valve core and the shell is blown back to the discharge port of the metering silo, preventing the powder from falling into the gap, thereby achieving a sealing effect and breaking the arch of the material at the discharge port of the metering silo; air is also blown to the discharge port of the metering silo through the second air supply valve to break the arch of the material at the discharge port of the metering silo. Preferably, the blowing direction of the second air supply valve and the blowing direction of the first air supply valve are staggered, which can achieve better sealing and arch breaking effects.

[0073] This embodiment also provides a scraper plate on the valve teeth of the valve core. Multiple scrapers are provided and spaced apart on different valve teeth. When the material distributing device rotates, the scraper plates on the valve teeth scrape off the material accumulated in the gap between the valve core and the housing.

[0074] After the material is unloaded, the rotation speed of the rotary distributing valve is increased in this embodiment, and the residual material in the mixing tank, the rotary distributing valve and the conveying pipeline is further delivered by means of pressure relief, thereby ensuring the accuracy of the conveying weight.

[0075] In summary, the material conveying control method of this embodiment improves conveying accuracy by intelligently controlling the servo motor's speed to compensate for the fill rate of the rotary dispensing valve. Closed-loop control enables quantitative material delivery and precise control of conveying speed and conveying weight errors with online deviation correction. The implementation of closed-loop control and online deviation correction makes material conveying more flexible, and conveying time and weight can be adjusted arbitrarily on the material conveying system's touchscreen.

[0076] The purpose of the above embodiments is to exemplify and deduce the technical solution of the present invention, and to fully describe the technical solution, purpose and effect of the present invention. Its purpose is to enable the public to have a more thorough and comprehensive understanding of the disclosed content of the present invention, and it does not limit the scope of protection of the present invention.

[0077] The above embodiments are not exhaustive and may include many other embodiments not listed above. Any replacements and improvements made without violating the concept of the present invention are within the scope of protection of the present invention.

Claims

1. A material conveying control method, characterized in that: include: Calculating a first rotational speed of a servo motor according to a given material discharge speed, a volume of a material trough in the material distributing device, a number of material troughs in the material distributing device, and a material density, wherein the servo motor is used to drive the material distributing device to rotate, and the material distributing device is provided with a plurality of material distributing troughs along a circumferential direction; During the material conveying process, the first weight of the metering silo is measured in real time, and the actual unloading weight and actual unloading speed are calculated based on the first weight and the second weight at a preset historical moment; Calculate theoretical unloading weight based on given unloading speed and the time difference between current moment and preset historical moment; When the difference between the actual material discharge weight and the theoretical material discharge weight exceeds a preset range, the second speed of the servo motor is determined according to the actual material discharge speed, the given material discharge speed and the actual speed of the servo motor until the material is transported; The material distribution equipment is a rotary material distribution valve, the valve core of the rotary material distribution valve is provided with valve teeth, and two adjacent valve teeth form the material distribution trough. During the positive pressure conveying process of the material, the following steps are also included: Calculate the unloading time of the material distribution chute according to the tooth height of the valve teeth; Calculate the maximum speed of the servo motor according to the unloading time and the angle of the feed chute in the circumferential direction; When the first speed or the second speed exceeds the maximum speed, sending a warning signal; The rotary dividing valve has a valve core and a shell, and there is a gap between the valve core and the inner wall of the shell. The rotary dividing valve is provided with a first air supply valve and a second air supply valve. The first air supply valve and the second air supply valve are arranged adjacent to the inlet of the rotary dividing valve. When the rotary dividing valve rotates, air is blown to the discharge port of the metering silo through the first air supply valve, so that the material accumulated in the gap is blown back to the discharge port, and the material at the discharge port is broken, and / or the second air supply valve is used to blow air to the discharge port of the metering silo to break the arch of the material at the discharge port. The blowing direction of the second air supply valve and the blowing direction of the first air supply valve are staggered.

2. The material conveying control method according to claim 1, characterized in that: Determining a second rotational speed of the servo motor according to the actual material feeding speed, the given material feeding speed, and the actual rotational speed of the servo motor includes: Calculating the ratio of the given material feeding speed to the actual material feeding speed; The product of the ratio and the actual rotational speed is calculated to obtain the second rotational speed.

3. The material conveying control method according to claim 1, wherein: The valve core is provided with valve teeth, and when the rotary distributing valve rotates, the materials accumulated in the gap are scraped off by the scraper plates on the valve teeth.

4. Material conveying system, characterized in that, include: A metering silo, a weighing device, a material distribution equipment, a pneumatic conveying component, a control device, a servo motor, and a receiving silo. The metering silo is used for temporarily storing materials, the weighing device is used to weigh the materials in the metering silo, the feed inlet of the material distribution equipment is connected to the metering silo, the feed outlet of the material distribution equipment is connected to the pneumatic conveying component, the feed outlet of the pneumatic conveying component is connected to the receiving silo, the servo motor is electrically connected to the material distribution equipment, the control device is electrically connected to the servo motor, and the material conveying control method according to any one of claims 1 to 3 runs on the control device.

5. The material conveying system according to claim 4, characterized in that: It also includes a frame and a conveying pipeline. The discharge port of the pneumatic conveying component is connected to a hose. The hose is fixed on the frame. The first end of the conveying pipeline is connected to the hose. The second end of the conveying pipeline is connected to the receiving silo.

6. The material conveying system according to claim 4, wherein: The rotary dispensing valve has a valve core, on which a plurality of valve teeth are distributed circumferentially. A plurality of scraper plates are also provided. The scraper plates are installed on the top ends of the valve teeth and are distributed on the plurality of valve teeth at intervals. The scraper plates are made of flexible material.

7. The material conveying system according to claim 4, wherein: A baffle plate is installed obliquely in the rotary distributing valve, and the feed port of the rotary distributing valve is divided into a feed chamber and a baffle chamber by the baffle plate. An anti-stuck block is fixed in the baffle chamber, and the anti-stuck block has a plurality of tooth-shaped protrusions, and both sides of the protrusion are inclined surfaces, and the inclined surfaces are arranged obliquely downward from the top of the protrusion to both sides of the protrusion. The bottom of the anti-stuck block is provided with an arc surface, and an avoidance portion is provided at the position where the arc surface intersects with the root of the protrusion.

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