A feeding device and method for slurry stirring

Abstract

The application discloses a feeding device and method for slurry stirring, wherein the feeding device comprises a storage module, the storage module comprises a storage hopper and a vibrator, the vibrator is fixed outside the storage hopper; a conveying module, the conveying module comprises a conveying cylinder, one end of the conveying cylinder is communicated with the storage hopper, a conveying screw is arranged in the conveying cylinder, and the conveying screw is driven to rotate by a first power device; a sensing module; and a control module, the control module is used for acquiring a load current, comparing the load current with a preset threshold value, adjusting the rotating speed of the conveying screw based on the comparison result, and matching the duty cycle of the vibrator based on the comparison result, so that the vibrator works at the matched duty cycle. Through real-time acquisition of the load current and comparison with the preset threshold value, the rotating speed of the conveying screw and the duty cycle of the vibrator are dynamically adjusted, the screw and the vibrator work cooperatively, and therefore the powder characteristics fluctuation is adaptively adjusted, the powder blocking and overload are prevented, and the energy consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of conveyor technology, and in particular to a feeding device and method for slurry mixing. Background Technology

[0002] Batter mixing is an indispensable and crucial step in many industrial sectors, including food processing, chemical production, and building materials manufacturing. Taking the food processing industry as an example, in the industrial production of processed meat products such as crispy pork, the battering process directly affects the product's texture and quality—raw meat strips need to be evenly coated with a batter or starch paste before being deep-fried to form a crispy outer shell. A continuous and stable supply of batter is a prerequisite for ensuring uniform battering and production efficiency; however, numerous technical challenges in the battering process have long constrained the improvement of product quality.

[0003] Currently, feeding devices used for slurry mixing in the food processing industry typically employ screw conveyors to quantitatively supply powders. However, powders such as flour and starch have physical characteristics such as small particle size, low bulk density, easy dust generation, easy agglomeration, and poor flowability. Screw conveyors present the following problems: In actual production, parameters such as the bulk density, moisture content, and degree of agglomeration of the powder fluctuate with environmental conditions and batch variations, leading to dynamic changes in conveying resistance. Under constant speed or open-loop control modes, increased load can easily cause poor conveying, material blockage, or even motor overload shutdown; conversely, decreased load may result in excessive feeding. To improve powder flowability and prevent bridging and blockage, existing devices typically add vibrators to assist in breaking up bridging in silos or conveying pipelines. However, existing vibrators often operate on a timed start-stop or manual adjustment basis. When conveying resistance increases, the vibrator cannot automatically increase vibration intensity or extend vibration time to assist in unblocking; when conveying is smooth, the vibrator may still continuously vibrate without contact, causing unnecessary energy consumption and equipment fatigue damage. Summary of the Invention

[0004] Therefore, in order to overcome the above-mentioned shortcomings, the present invention provides a feeding device and method for slurry mixing. By collecting the load current in real time and comparing it with a preset threshold, the rotational speed of the conveying screw and the duty cycle of the vibrator are dynamically adjusted so that the screw and the vibrator work together, thereby adapting to the fluctuation of powder characteristics, preventing material blockage and overload, reducing energy consumption, and improving the stability of slurry conveying and product quality.

[0005] On one hand, the present invention provides a feeding device for slurry mixing, comprising: A storage module, which includes a storage hopper and a vibrator, wherein the vibrator is fixed to the outside of the storage hopper; A conveying module includes a conveying cylinder, one end of which is connected to a storage hopper. A conveying screw is installed inside the conveying cylinder, and a first power device drives the conveying screw to rotate around its own axis. The sensing module is used to collect the load current of the first power unit and the rotational speed of the conveying screw in real time; The control module is electrically connected to the sensing module, the vibrator, and the first power device. The control module is used to acquire the load current, compare the load current with a preset threshold, adjust the rotational speed of the conveying screw based on the comparison result, and match the duty cycle of the vibrator based on the comparison result so that the vibrator operates at the matched duty cycle.

[0006] Furthermore, the preset threshold includes a light load threshold and an overload threshold; Based on the comparison results, the specific method for adjusting the rotational speed of the conveying screw is as follows: ; in, n k For the first k The rotational speed of the conveying screw during each cycle; n k-1 For the first k - The rotational speed of the conveying screw during one cycle; K p This is the proportionality coefficient; I 0 represents the optimal load limit; I k For the first k Load current during each cycle; I 1 represents the light load threshold; I 2 represents the overload threshold.

[0007] Furthermore, the control module is also used to generate a backflush unblocking command and send it to the first power device and the vibrator when the load current is greater than the overload threshold and the duration exceeds the preset time, so that the first power device drives the conveying screw to rotate in the opposite direction, and at the same time makes the vibrator vibrate continuously at a preset frequency for a preset number of times, with each vibration lasting for a second preset time.

[0008] Furthermore, the feeding device also includes a discharging module, which includes: The discharge hopper is connected to the discharge port of the conveying cylinder via a connecting pipe, and a vertically downward-extending discharge pipe is provided at the bottom of the discharge hopper; A baffle is installed at the connection between the discharge hopper and the discharge pipe. The baffle is driven by a second power device to move linearly in the horizontal direction to close or open the connection between the discharge hopper and the discharge pipe.

[0009] Furthermore, the control module is also used to calculate the pre-closing advance time based on the rotational speed of the conveying screw, so as to control the second power unit to drive the baffle to close the connection between the discharge bin and the discharge pipe after the pre-closing advance time has expired.

[0010] Furthermore, the specific method for calculating the pre-closing advance time based on the rotational speed of the conveying screw is as follows: ; in, t 1 represents the lead time for pre-closure; H This refers to the length of the material feeding pipe; ρ This is a correction factor; v c This refers to the overall falling speed of the powder within the discharge pipe.

[0011] Furthermore, the method for determining the overall falling speed of the powder within the discharge pipe is as follows: ; in, v p The free fall speed of the powder; ε The push coupling coefficient; Q The volume conveyed per revolution of the conveying screw; n t The real-time rotational speed at time t is the rotational speed of the conveying screw collected in real time by the sensing module. B This represents the average cross-sectional area of ​​the feed pipe.

[0012] Furthermore, the sensing module is also used to collect material level data; the control module is also used to acquire material level data, calculate the real-time material level change rate based on the material level data, and dynamically adjust the rotational speed of the conveying screw based on the deviation between the real-time material level change rate and the target material level change rate using a PID control algorithm.

[0013] On the other hand, the present invention provides a feeding control method for slurry mixing, used to control the above-mentioned feeding device for slurry mixing, comprising the following steps: Obtain the load current of the first power unit and the rotational speed of the conveying screw; The load current is compared with preset thresholds, which include a light load threshold and an overload threshold. Based on the comparison results, the rotational speed of the conveying screw is adjusted; The duty cycle of the vibrator is matched based on the comparison results, and the vibrator is controlled to operate at the matched duty cycle.

[0014] The present invention has the following advantages: This invention uses a sensing module to collect the load current of the first power unit and the rotational speed of the conveying screw in real time. The control module compares the load current with a preset threshold and dynamically adjusts the screw's rotational speed based on the comparison result. When the load current increases, the control module automatically reduces the screw speed to prevent motor overload and shutdown, and material blockage. When the load current decreases, the speed can be appropriately increased to ensure feeding efficiency. This invention can adapt to real-time fluctuations in parameters such as powder bulk density, moisture content, and agglomeration degree, improving the stability and reliability of the conveying process. This invention matches the vibrator's duty cycle with the load current comparison result, enabling the vibrator to automatically adjust its working intensity according to actual changes in conveying resistance. When the load current exceeds a set threshold, the control module automatically increases the vibrator's duty cycle, enhancing the vibration amplitude or extending the vibration time to assist in breaking up and clearing blockages. When the load current is within the normal range, the vibrator operates with a lower duty cycle or works intermittently, reducing energy waste and mechanical fatigue damage caused by continuous idle vibration. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the logic structure of the feeding device; Figure 2 This is a schematic diagram of the feeding device; Figure 3 yes Figure 2 The diagram shows the structure of the material storage module in the feeding device. Figure 4 yes Figure 2 A schematic diagram of the conveying module in the feeding device shown; Figure 5 yes Figure 2 A schematic diagram of the discharge module in the feeding device shown; In the picture: 100. Sensing module; 200. Control module; 300. Material storage module; 310. Material storage hopper; 320. Vibrator; 330. Feed pipe; 400. Conveying module; 410. Conveying cylinder; 420. Conveying screw; 430. First power unit; 440. Discharge port; 500. Discharge module; 510. Connecting pipe; 520. Second power unit; 530. Discharge pipe; 540. Discharge hopper; 550. Baffle; 600. Interactive module. Detailed Implementation

[0016] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0017] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0018] As described in the background section, in actual production, parameters such as the bulk density, moisture content, and agglomeration degree of powder materials fluctuate with environmental conditions and batch variations, leading to dynamic changes in conveying resistance. Under constant speed or open-loop control modes, increased load can easily cause poor conveying, material blockage, or even motor overload and shutdown; conversely, decreased load may result in excessive material supply. To improve powder flowability and prevent bridging and blockage, existing devices typically add vibrators to assist in breaking up bridging in silos or conveying pipelines. However, existing vibrators often operate using timed start / stop or manual adjustment. When conveying resistance increases, the vibrator cannot automatically increase vibration intensity or extend vibration time to assist in clearing blockages; when conveying is smooth, the vibrator may still continuously vibrate without contact, causing unnecessary energy consumption and equipment fatigue damage.

[0019] Example 1: Therefore, in order to solve the above-mentioned technical problems existing in the prior art, this embodiment provides a feeding device for slurry mixing, such as... Figure 1 , Figure 2 As shown, it includes: Storage module 300, such as Figure 3 As shown, the storage module includes a storage hopper 310 and a vibrator 320, with the vibrator fixed to the outside of the storage hopper. Conveyor module 400, such as Figure 4 As shown, the conveying module includes a conveying cylinder 410, one end of which is connected to a storage hopper. A conveying screw 420 is provided inside the conveying cylinder, and the conveying screw is driven to rotate around its own axis by a first power device 430. The sensing module 100 is used to collect the load current of the first power unit and the rotational speed of the conveying screw in real time; The control module 200 is electrically connected to the sensing module, the vibrator, and the first power device. The control module is used to acquire the load current, compare the load current with a preset threshold, adjust the rotation speed of the conveying screw based on the comparison result, and match the duty cycle of the vibrator based on the comparison result so that the vibrator operates with the matched duty cycle.

[0020] Specifically, the storage hopper can be a conical hopper, a square hopper, or a cylindrical hopper, preferably made of stainless steel (such as 304 or 316L). The vibrator can be an electromagnetic vibrator, a pneumatic vibrator (such as a piston or ball bearing vibrator), or an eccentric motor vibrator, selected according to the on-site air and power supply conditions. The conveying cylinder can be a cylindrical stainless steel tube with a smooth inner wall; the length-to-diameter ratio is determined according to the conveying distance and powder characteristics. Inspection ports or observation windows can be provided on the cylinder. The conveying screw can be a constant-pitch screw, a variable-pitch screw, or a combined screw with stirring blades. The primary power unit can be a servo motor or a variable-frequency geared motor. The sensing module can include a current detection unit and a speed detection unit. The current detection unit can be a current transformer, a Hall current sensor, or a current sampling circuit built into the motor driver; the speed detection unit can be a rotary encoder (incremental or absolute), a Hall proximity switch (with a magnet at the screw shaft end), or the speed feedback signal from the motor driver itself. The control module can be a programmable logic controller (PLC), a microcontroller (such as the STM32 series), an embedded industrial control board, or a dedicated motion controller, and is equipped with analog input / output ports and digital I / O interfaces, with built-in comparators and PID control algorithms.

[0021] After the device is started, powder (such as flour or starch) is first added to the storage hopper. The first power unit is then activated to drive the conveying screw to rotate, while the vibrator is activated at the initial duty cycle to assist in breaking up arches. Under the action of gravity, the powder falls into the feed inlet of the conveying cylinder and is continuously pushed towards the discharge end by the rotation of the screw, entering the subsequent mixing process. During continuous operation, the sensing module collects the load current value of the first power unit and the current speed of the conveying screw in real time and sends the data to the control module. The control module compares the real-time load current with at least one internally stored threshold. When the load current exceeds the high threshold, it indicates a significant increase in conveying resistance (possibly due to powder agglomeration, bridging, increased moisture content, etc.). The control module immediately outputs a command to reduce the output frequency or voltage of the first power unit, causing the conveying screw speed to decrease, thereby reducing the load and preventing motor overload or stall. Simultaneously, the control module increases the vibrator's duty cycle proportionally or according to a preset mapping relationship based on the degree of load current exceeding the limit (e.g., from 30% to 70% or even 100%), causing the vibrator to impact the hopper wall with stronger amplitude and longer vibration time, disrupting the powder bridging structure. When the load current is below the low threshold, it indicates lower conveying resistance and better material flowability. The control module appropriately increases the conveying screw speed to increase the feed rate and improve production efficiency. At the same time, it reduces the vibrator's duty cycle (e.g., to 10% or intermittent start-stop, such as working for 2 seconds and stopping for 5 seconds) to avoid continuous idling causing energy waste and mechanical fatigue. When the load current is between the high and low thresholds, it indicates that the conveying status is normal. The control module maintains the current screw speed and vibrator duty cycle unchanged, or only makes fine adjustments.

[0022] This embodiment uses a sensing module to collect the load current of the first power unit and the rotational speed of the conveying screw in real time. The control module compares the load current with a preset threshold and dynamically adjusts the rotational speed of the conveying screw based on the comparison result. When the load current increases (indicating increased conveying resistance), the control module can automatically reduce the screw speed to prevent motor overload shutdown and material blockage. When the load current decreases (indicating smooth conveying), the rotational speed can be appropriately increased to ensure feeding efficiency. This allows the system to adapt to real-time fluctuations in parameters such as powder bulk density, moisture content, and agglomeration degree, improving the stability and reliability of the conveying process. This invention matches the vibrator's duty cycle with the load current comparison result, enabling the vibrator to automatically adjust its working intensity according to the actual changes in conveying resistance. When the load current exceeds a set threshold (indicating bridging or blockage), the control module automatically increases the vibrator's duty cycle, enhancing the vibration amplitude or extending the vibration time to assist in breaking up and clearing blockages. When the load current is within the normal range, the vibrator operates with a lower duty cycle or works intermittently, reducing energy waste and mechanical fatigue damage caused by continuous idle vibration.

[0023] In this embodiment, as Figure 3As shown, the storage module may further include a feed pipe 330, which is fixedly connected to the top of the storage hopper and communicates with the inside of the storage hopper for replenishing powder into the storage hopper. The feed pipe may be made of stainless steel round or square pipe, and the pipe opening may be equipped with a quick-connect fitting or flange for sealing connection with the upstream powder conveying pipeline (such as a pneumatic conveying system or screw feeder). To prevent powder from accumulating or bridging in the feed pipe, the feed pipe may be designed to extend downwards at an angle into the storage hopper, preferably with an angle greater than the angle of repose of the powder (usually 45°~60°). In addition, manual or pneumatic butterfly valves or slide gate valves may be optionally installed on the feed pipe for cutting off the feed during maintenance or when material is stopped; dust removal interfaces or dust covers may also be installed on the pipeline to reduce dust overflow during feeding.

[0024] In this embodiment, the preset threshold may include a light load threshold and an overload threshold; Based on the comparison results, the specific method for adjusting the rotational speed of the conveying screw is as follows: ; in, n k For the first k The rotational speed of the conveying screw during each cycle; n k-1 For the first k - The rotational speed of the conveying screw during one cycle; K p This is the proportionality coefficient. r / ( min · A ); I 0 represents the optimal load limit; I k For the first k Load current during each cycle; I 1 represents the light load threshold; I 2 represents the overload threshold.

[0025] Specifically, this embodiment divides the load current into three ranges, each corresponding to a different speed adjustment strategy, thus achieving closed-loop proportional regulation based on real-time load. When I k < I At time 1, the load current is below the light load threshold, indicating low conveying resistance, good powder flowability, and the current feeding speed is lower than the equipment capacity. n k-1 + K p ( I 0- I k The rotational speed of the conveying screw is increased by means of [method name missing]. I 0 represents the preset optimal load limit (usually slightly below the overload threshold).I 2), I 0- I k This reflects the difference between the current load and the ideal load limit. The larger the difference, the larger the speed increment, resulting in a rapid increase in feeding efficiency. As the speed increases, the load current gradually rises, and the increment automatically decreases. When... I 1≤ I k < I At time 2, the load current is between the light load threshold and the overload threshold, indicating that the transmission resistance is moderate and the motor is operating within a safe and efficient load range. At this time, the control module maintains the speed from the previous cycle unchanged and does not make any adjustments. I k ≥ I At time 2, if the load current reaches or exceeds the overload threshold, it indicates excessive conveying resistance and a risk of material blockage, bridging, or motor overload. The control module follows... n k-1 - K p ( I k - I 2) Reduce the speed of the conveying screw. Among them, ( I k - I 2) For current deviations exceeding the overload threshold, the larger the deviation, the greater the speed reduction to quickly decrease the load. The speed reduction process stops once the load current returns to the normal range. The above adjustments are executed cycle-by-cycle with a fixed control period (e.g., every 0.1 to 1 second). The proportional coefficient can be determined through on-site debugging, typically ranging from 0.01 to 0.5 (specifically calculated based on the ratio of the motor's rated speed to its rated current). Through this segmented proportional adjustment method, the conveying screw speed can smoothly and quickly follow load changes, automatically accelerating under light loads to improve production efficiency and automatically decelerating under overloads to avoid malfunctions. This confines the load current within a reasonable range, achieving adaptive and stable control of the powder conveying process.

[0026] In this embodiment, the control module is also used to generate a backlash unblocking command and send it to the first power device and the vibrator when the load current is greater than the overload threshold and the duration exceeds the preset time, so that the first power device drives the conveying screw to rotate in the opposite direction, and at the same time the vibrator continuously vibrates at a preset frequency for a preset number of times, and each vibration lasts for a second preset time.

[0027] Specifically, when the load current continuously exceeds the overload threshold for a preset time (e.g., 3-10 seconds), it indicates that the powder may have formed a strong bridging or compacted agglomerate inside the conveyor cylinder or at the outlet of the storage hopper. Simply reducing the speed of the conveying screw is insufficient to improve the blockage problem. At this time, the control module sends a reverse rotation command to the first power unit, causing the conveying screw to rotate in the opposite direction at a preset reverse speed (e.g., 20%-50% of the rated speed). The reverse rotation pushes the material that was originally squeezed forward backward, breaking the pressure at the blockage point, and at the same time loosens the compacted powder inside the conveyor cylinder and brings it back to the storage hopper, thereby releasing the blocking pressure in the conveying channel. While the screw is rotating in the reverse direction, the control module sends a strong vibration command to the vibrator, causing the vibrator to vibrate continuously at a preset frequency (e.g., 50 Hz-100 Hz) for a preset number of times (e.g., 3-10 times), with each vibration lasting for a second preset time (e.g., 1-3 seconds). A short interval (e.g., 0.5-1 second) can be set between two adjacent vibrations. This high-intensity, intermittent pulsed vibration can transmit impact energy to the hopper wall, breaking up the powder bridging structure and causing the blocked material to collapse and fall. After the backflushing unblocking process is completed, the control module automatically exits the unblocking mode and restarts forward conveying according to the aforementioned segmented proportional adjustment strategy. At this time, the load current will usually decrease. If it is still higher than the overload threshold, the backflushing unblocking can be repeated once. If the load current does not improve after 2 to 3 consecutive executions, the control module will issue an audible and visual alarm, prompting manual intervention. In this embodiment, through backflushing unblocking, when conventional speed regulation cannot eliminate severe blockages, the material channel can be actively cleared by the synergistic effect of screw reversal and strong vibration pulses. This improves the adaptability and self-recovery capability of the feeding device to harsh working conditions and reduces the frequency of manual cleaning of blockages.

[0028] In this embodiment, as Figure 1 , Figure 2 As shown, the feeding device also includes a discharging module 500, such as... Figure 5 As shown, the discharge module includes: The discharge hopper 540 is connected to the discharge port 440 of the conveying cylinder via a connecting pipe 510, and a vertically downward-extending discharge pipe 530 is provided at the bottom of the discharge hopper. Baffle 550 is located at the connection between the discharge hopper and the discharge pipe. The second power device 520 drives the baffle to move linearly in the horizontal direction to close or open the connection between the discharge hopper and the discharge pipe.

[0029] Specifically, the discharge hopper can be made of stainless steel (304 or 316L), with its top connected to the connecting pipe flange. An internal guide ramp or baffle can be installed to smoothly collect powder or slurry to the bottom outlet. For easy observation of the discharge status, a transparent observation window (such as tempered glass or plexiglass) can be provided on the side wall of the discharge hopper. The connecting pipe can be a flexible hose (such as rubber or silicone corrugated pipe) or a rigid stainless steel round pipe. The discharge pipe extends vertically downwards, with its end connecting to the subsequent mixing tank. The baffle can be a flat structure, made of wear-resistant stainless steel or PTFE-coated steel plate. The shape of the baffle matches the connection port (usually rectangular or circular), and its edges can be fitted with sealing strips (such as silicone or polyurethane) to ensure a tight seal when closed and prevent leakage. The second power unit can be a linear motion actuator, including but not limited to cylinders, electric push rods, and linear modules (screw + motor). Under normal feeding conditions, the control module sends an opening command to the second power unit, driving the baffle to move horizontally and fully open the connection port between the discharge hopper and the discharge pipe. Powder or slurry discharged from the conveyor outlet falls into the discharge hopper via the connecting pipe, then enters the discharge pipe through the open connecting port, and finally falls into the downstream mixing equipment or slurry machine. When it is necessary to stop feeding, replace the downstream container, or clean the equipment, the control module sends a shut-off command to the second power unit, the baffle moves horizontally in the opposite direction, completely closing the connecting port and cutting off the material falling channel.

[0030] For example, the control module is also used to calculate the pre-closing advance time based on the rotational speed of the conveying screw, so as to control the second power unit to drive the baffle to close the connection between the discharge bin and the discharge pipe after the pre-closing advance time has ended.

[0031] In this embodiment, the specific method for calculating the pre-closing advance time based on the rotational speed of the conveying screw is as follows: ; in, t 1 represents the lead time for pre-closure; H This refers to the length of the material feeding pipe; ρ This is a correction factor; v c This refers to the overall falling speed of the powder within the discharge pipe.

[0032] In this embodiment, the overall falling speed of the powder in the discharge pipe is determined as follows: ; in, v p The free fall speed of the powder; ε The push coupling coefficient; Q The volume conveyed per revolution of the conveying screw; n tThe real-time rotational speed at time t is the rotational speed of the conveying screw collected in real time by the sensing module. B This represents the average cross-sectional area of ​​the feed pipe.

[0033] Specifically, when upstream material supply needs to be stopped (e.g., production batch ends, downstream equipment needs drum replacement or cleaning), if the baffle is closed directly, a portion of powder or slurry will remain in the discharge pipe, resulting in material waste or contamination. By calculating the pre-closing lead time, the control module can issue a baffle closing command in advance before upstream material supply stops, ensuring that the material in the discharge pipe is emptied when the baffle is closed.

[0034] In this embodiment, the sensing module is also used to collect material level data; the control module is also used to acquire material level data, calculate the real-time material level change rate based on the material level data, and dynamically adjust the rotational speed of the conveying screw based on the deviation between the real-time material level change rate and the target material level change rate using a PID control algorithm.

[0035] Specifically, the sensing module may also include an additional material level detection unit for real-time monitoring of the material height in downstream containers (e.g., a mixing tank or a hopper of a slurry machine connected to the outlet of the discharge pipe 530). Optional material level sensor types include non-contact sensors (e.g., ultrasonic level gauges, radar level gauges, laser rangefinders, etc.), contact sensors (e.g., rotary paddle level switches, capacitive level gauges, plumb bob level gauges), and pressure sensors (e.g., hydrostatic level transmitters or weighing modules). The control module reads the current material level value in each control cycle (e.g., every 0.5 seconds) and calculates the real-time material level change rate using first-order differential or moving average filtering. To suppress noise, the average change rate of the most recent 3-5 cycles can be used. A positive change rate indicates a rising material level (feeding greater than discharging), a negative value indicates a falling material level (discharging greater than feeding), and zero indicates dynamic equilibrium. The target material level change rate is set according to production needs. The control module inputs the deviation between the real-time material level change rate and the target change rate into the PID controller, outputs a speed correction amount, and adds it to the speed command. In this device, load current control and material level change rate control can work together. For example, the material level change rate can be the primary control target, and the load current can be used as a safety constraint. When the load current approaches the overload threshold, the speed increment of the material level PID is limited or cleared. After normalizing the load current deviation and the material level change rate deviation, they are summed according to their weights to generate the total speed adjustment amount. The weights can be set on-site; for example, the material level weight is higher when production is stable, and the current weight is higher when the powder has poor flowability. When the load current exceeds the high threshold, load current control takes the lead; when the load current falls back to the normal range, material level PID control takes over.

[0036] Example 2: This embodiment provides a feeding control method for slurry mixing, used to control a feeding device for slurry mixing described in Embodiment 1, comprising the following steps: S100: Obtain the load current of the first power unit and the rotational speed of the conveying screw; Specifically, the control module collects the load current value of the first power unit and the current rotational speed of the conveying screw in real time through the sensing module. The sensing module may include a current detection unit and a speed detection unit: the current detection unit may use a current transformer, a Hall current sensor, or the current sampling circuit built into the motor driver to obtain the load current; the speed detection unit may use a rotary encoder (incremental or absolute), a Hall proximity switch (in conjunction with the magnet at the end of the screw shaft), or the speed feedback signal of the motor driver itself to obtain the rotational speed of the conveying screw in real time. The collected load current and speed data are sent to the control module.

[0037] S200: Compare the load current with a preset threshold, which includes a light load threshold and an overload threshold; Specifically, the control module has pre-stored light load and overload thresholds. The light load threshold is used to determine if the conveying resistance is too low (i.e., insufficient material supply), and the overload threshold is used to determine if the conveying resistance is too high (i.e., there is a risk of material blockage or overload). The control module compares the real-time load current with these two thresholds to divide the load into three intervals: I k < I 1 (Light load section) I 1≤ I k < I 2 (Normal range) I k ≥ I 2 (Overload range).

[0038] S300: Adjust the rotational speed of the conveying screw based on the comparison results; Specifically, the control module dynamically adjusts the speed of the conveying screw according to a segmented proportional adjustment formula based on the range of the load current: when I k < I In range 1 (light load), it indicates low conveying resistance, good material flowability, and the current feeding speed is lower than the equipment capacity. The control module follows... n k = n k-1+ K p ( I 0- I k Increase the rotational speed of the conveying screw. Difference (I 0- I k The larger the value, the greater the speed increment, thus rapidly improving feeding efficiency; as the speed increases, the load current gradually rises, and the increment automatically decreases. When I 1≤ I k < I At point 2 (normal range), it indicates that the conveying resistance is moderate and the motor is operating within a safe and efficient load range. The control module maintains the speed from the previous cycle unchanged. n k = n k-1 No adjustment is made. When I k ≥ I When the threshold is 2 (overload range), it indicates excessive conveying resistance, posing a risk of material blockage, bridging, or motor overload. The control module will then... n k-1 - K p ( I k - I 2) Reduce the speed of the conveying screw. Deviation ( I k - I 2) The larger the value, the greater the speed reduction, in order to quickly reduce the load and prevent the motor from overloading and shutting down; the speed reduction process stops after the load current returns to the normal range. The above adjustment can be executed cycle by cycle with a fixed control period (e.g., every 0.1 seconds to 1 second), and the proportional coefficient is determined through on-site debugging (usually ranging from 0.01 to 0.5). Through this segmented proportional adjustment, the speed can smoothly and quickly follow the load changes, achieving adaptive and stable transmission.

[0039] S400: Based on the comparison results, match the duty cycle of the vibrator and control the vibrator to operate at the matched duty cycle.

[0040] Specifically, the control module synchronously matches the vibrator's duty cycle based on the comparison between the load current and a preset threshold. When the load current is within the normal range, indicating normal conveying, the vibrator operates at a lower duty cycle (e.g., 10%–30%) or uses an intermittent working mode (e.g., working for 2 seconds and stopping for 5 seconds) to reduce energy consumption. When the load current exceeds the overload threshold, it indicates increased conveying resistance. The control module increases the vibrator's duty cycle proportionally or according to a preset mapping relationship based on the degree of load current exceeding the limit (e.g., from 30% to 70% or even 100%), causing the vibrator to impact the hopper wall with stronger vibration amplitude and longer vibration time, disrupting the powder bridging structure and promoting smooth material flow. When the load current is below the light load threshold, indicating low conveying resistance and good material flowability, the control module further reduces the vibrator's duty cycle (e.g., reducing it to 10% or stopping vibration completely). By dynamically matching the duty cycle of the vibrator with the load current comparison result, the vibrator and the conveying screw work together, which not only ensures effective arch breaking when there is a tendency to blockage, but also saves energy and extends the service life of the equipment under smooth operation.

[0041] Furthermore, when the load current exceeds the overload threshold and the duration exceeds a preset time (e.g., 3-10 seconds), the control module also controls the first power unit to drive the conveying screw to rotate in the reverse direction (the reverse speed is 20%-50% of the rated speed), while simultaneously causing the vibrator to vibrate continuously at a preset frequency (e.g., 50-100Hz) for a preset number of times (e.g., 3-10 times), with each vibration lasting for a second preset time (e.g., 1-3 seconds). After the backflushing and unblocking are completed, forward conveying is automatically restored and the above steps are repeated.

[0042] S500: The control method may further include: The material level data is collected, and the speed of the conveying screw is dynamically adjusted using a PID control algorithm.

[0043] Specifically, the sensing module also collects real-time material level data in downstream containers (e.g., mixing tanks or hoppers of a slurry machine connected to the outlet of the discharge pipe 530) through a material level detection unit (such as an ultrasonic level gauge, a capacitive continuous level gauge, or a pressure sensor). The control module reads the current material level value in each control cycle (e.g., every 0.5 seconds) and calculates the real-time material level change rate using first-order difference or moving average filtering. Simultaneously, a target material level change rate is set according to production requirements (e.g., 0% for constant level control, or a predetermined slope for rising / falling). The control module inputs the deviation between the real-time material level change rate and the target change rate into the PID controller, calculates the speed correction using a discrete formula, and adds it to the speed determined by S300 to obtain the final speed. When the load current approaches the overload threshold, the load current control of S300 is executed first (limiting or clearing the PID correction); when the load current is normal, the material level PID control dominates the adjustment, thereby achieving a dynamic balance between the supply and downstream demand, preventing overflow or material shortage.

[0044] S600: Calculates the pre-closing advance time based on the real-time rotational speed of the conveying screw collected by the sensor module, and controls the baffle to close with a delay.

[0045] Specifically, when it is necessary to stop feeding (e.g., at the end of a production batch, or when downstream equipment needs to change drums or be cleaned), the control module first reads the real-time rotational speed of the conveying screw, calculates the pre-closing advance time, and starts a delay timer with a timing length equal to the calculated closing advance time. During the timing period, the conveying screw continues to feed at its original rotational speed, while the material in the discharge pipe descends at a combined falling speed. After the timing period ends, the control module sends a closing command to the second power unit, driving the baffle to move horizontally and closing the connection between the discharge hopper and the discharge pipe. At this point, the last section of material in the discharge pipe is discharged from the outlet, achieving an empty pipe. If the calculated closing advance time is less than the minimum response time (e.g., 0.1 seconds), the minimum response time is used; if it is greater than the maximum allowable waiting time (e.g., 30 seconds), the maximum value is applied and a prompt is issued.

[0046] S700: Backflush deblocking control (enhanced treatment in case of severe blockage).

[0047] Specifically, during the execution of S300 or S500, if the load current is detected to have exceeded the overload threshold for a preset time (e.g., 3-10 seconds), the control module sends a reverse rotation command to the first power unit, causing the conveying screw to rotate in the opposite direction at a preset reverse speed (e.g., 20%-50% of the rated speed), pushing the forward-pressed material backward and releasing the blockage pressure in the conveying channel. Simultaneously, the control module sends a strong vibration command to the vibrator, causing it to vibrate continuously at a preset frequency (e.g., 50-100 Hz) for a preset number of times, with each vibration lasting for a second preset time (e.g., 1-3 seconds). A short interval (e.g., 0.5-1 second) can be set between adjacent vibrations to break up the powder bridging structure. After the backflushing and unblocking process is completed, the control module automatically exits the unblocking mode and resumes normal forward conveying and adjustment according to S300, S500, and S600. If the load current does not improve after 2-3 consecutive executions, the control module issues an audible and visual alarm, prompting manual intervention.

[0048] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A feeding device for slurry mixing, characterized in that, include: A storage module, which includes a storage hopper and a vibrator, wherein the vibrator is fixed to the outside of the storage hopper; A conveying module includes a conveying cylinder, one end of which is connected to a storage hopper. A conveying screw is installed inside the conveying cylinder, and a first power device drives the conveying screw to rotate around its own axis. The sensing module is used to collect the load current of the first power unit and the rotational speed of the conveying screw in real time; The control module is electrically connected to the sensing module, the vibrator and the first power device. The control module is used to acquire the load current, compare the load current with a preset threshold, adjust the speed of the conveying screw based on the comparison result, and match the duty cycle of the vibrator based on the comparison result so that the vibrator works with the matched duty cycle. The preset thresholds include a light load threshold and an overload threshold; Based on the comparison results, the specific method for adjusting the rotational speed of the conveying screw is as follows: ； in, n k For the first k The rotational speed of the conveying screw during each cycle; n k-1 For the first k - The rotational speed of the conveying screw during one cycle; K p This is the proportionality coefficient; I 0 represents the optimal load limit; I k For the first k Load current during each cycle; I 1 represents the light load threshold; I 2 represents the overload threshold; The control module is also used to generate a backlash unblocking command and send it to the first power device and the vibrator when the load current is greater than the overload threshold and the duration exceeds the preset time, so that the first power device drives the conveying screw to rotate in the opposite direction, and at the same time the vibrator vibrates continuously at a preset frequency for a preset number of times, with each vibration lasting for a second preset time.

2. The feeding device for slurry mixing according to claim 1, characterized in that, The feeding device further includes a discharging module, which includes: The discharge hopper is connected to the discharge port of the conveying cylinder via a connecting pipe, and a vertically downward-extending discharge pipe is provided at the bottom of the discharge hopper; A baffle is installed at the connection between the discharge hopper and the discharge pipe. The baffle is driven by a second power device to move linearly in the horizontal direction to close or open the connection between the discharge hopper and the discharge pipe.

3. The feeding device for slurry mixing according to claim 2, characterized in that, The control module is also used to calculate the pre-closing advance time based on the rotational speed of the conveying screw collected in real time by the sensing module, so as to control the second power unit to drive the baffle to close the connection between the discharge bin and the discharge pipe after the pre-closing advance time has expired.

4. The feeding device for slurry mixing according to claim 3, characterized in that, The specific method for calculating the pre-closing advance time based on the real-time rotational speed of the conveying screw collected by the sensing module is as follows: ； in, t 1 represents the lead time for pre-closure; H This refers to the length of the material feeding pipe; ρ This is a correction factor; v c This refers to the overall falling speed of the powder within the discharge pipe.

5. The feeding device for slurry mixing according to claim 4, characterized in that, The method for determining the overall falling speed of the powder in the discharge pipe is as follows: ； in, v p The free fall speed of the powder; ε The push coupling coefficient; Q The volume conveyed per revolution of the conveying screw; n t The real-time rotational speed at time t is the rotational speed of the conveying screw collected in real time by the sensing module. B This represents the average cross-sectional area of ​​the feed pipe.

6. The feeding device for slurry mixing according to claim 1, characterized in that, The sensing module is also used to collect material level data; the control module is also used to acquire material level data, calculate the real-time material level change rate based on the material level data, and dynamically adjust the rotation speed of the conveying screw based on the deviation between the real-time material level change rate and the target material level change rate using a PID control algorithm.

7. A method for controlling the feeding of slurry for mixing, used to control the feeding device for mixing slurry as described in any one of claims 1 to 6, characterized in that, Includes the following steps: Obtain the load current of the first power unit and the rotational speed of the conveying screw; The load current is compared with preset thresholds, which include a light load threshold and an overload threshold. Based on the comparison results, the rotational speed of the conveying screw is adjusted; The duty cycle of the vibrator is matched based on the comparison results, and the vibrator is controlled to operate at the matched duty cycle.

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