Needle-shaped fertilizer delivery device with dust suppression and method of use

Abstract

The present application relates to the field of fertilizer processing and material conveying equipment, in particular to a needle-shaped fertilizer conveying device with dust suppression and adsorption device and a method thereof; comprising a conveying frame, a conveying function part, a dust suppression and adsorption function part, an air guide function part, a vibration cleaning function part and a controller; the device separates the dust suppression shell inner cavity into a gravity settling chamber and a negative pressure adsorption chamber through a filter screen, and uses an eccentric cam mechanism to vibrate and clean the filter screen to prevent blockage; the core is that the outer surface of the ring-shaped conveying belt is provided with arrayed comb-shaped flexible bearing strips, and the comb tooth spacing is matched with the average length of the needle-shaped fertilizer; the present application can effectively accommodate and limit the posture of the needle-shaped fertilizer, avoid the material from rolling and being squeezed in the conveying process, effectively reduce the physical breaking rate and dust production from the source, and overcome the defects of conventional flat belt conveying such as easy breaking and dust production.

Description

Technical Field

[0001] This invention relates to the field of fertilizer processing and material conveying equipment, specifically to a needle-shaped fertilizer conveying device and method with a dust suppression and adsorption device. Background Technology

[0002] In the current manufacturing and packaging of needle-shaped fertilizers, strip-shaped or needle-shaped fertilizer granules with large length-to-diameter ratios need to be transferred across processes via conveying equipment. To achieve material handling, existing solutions generally use ordinary flat belt conveyors combined with conventional suction dust removal equipment. Due to the geometric characteristics of needle-shaped fertilizers, they are prone to lateral tumbling, mutual compression between materials, and physical breakage when conveyed on flat belt surfaces, releasing a large amount of dust. To address this dust, existing dust removal devices mostly use a constant airflow based on empirical values ​​for suction, and are equipped with vibrating filters at a fixed frequency. Cleaning is required; although the solution has basic dust collection capabilities, the constant air volume is difficult to adapt to the real-time fluctuations in material throughput and belt speed, which can easily cause insufficient local suction or mistakenly carry away qualified fertilizer particles; more importantly, fertilizer dust has strong hygroscopic properties, and after adhering to the filter screen, it is easy to turn into a semi-adhesive state or form highly adhesive clumps. Traditional fixed-frequency vibration cannot generate effective local resonance and peeling stress in the clump area, which eventually leads to rapid clogging of the filter screen, causing the entire conveying dust removal system to lose its continuous operation capability, and it is necessary to rely on manual shutdown and disassembly cleaning.

[0003] Therefore, how to effectively limit the orientation of needle-shaped fertilizers at the source of delivery to reduce breakage and dust generation, and how to solve the continuous problem of frequent clogging of the filter structure caused by hygroscopic dust, have become urgent technical problems to be solved. Summary of the Invention

[0004] To solve the above-mentioned technical problems, the present invention provides a needle-shaped fertilizer conveying device and method with a dust suppression and adsorption device. Specifically, the technical solution of the present invention is as follows:

[0005] A needle-shaped fertilizer conveying device with a dust suppression and adsorption unit includes:

[0006] Conveyor frame;

[0007] The conveying function unit, located on the conveyor frame, includes a driving roller and a driven roller respectively fixed to both ends of the conveyor frame, and an annular conveyor belt that is tensioned between the two rollers;

[0008] The outer surface of the annular conveyor belt is provided with arrayed comb-shaped flexible support strips, the spacing of which is suitable for accommodating needle-shaped fertilizers to be conveyed;

[0009] The dust suppression and adsorption functional unit is located above the middle section of the conveyor frame, and includes a sealed dust suppression shell fixed to the conveyor frame and a filter screen inclinedly arranged in the inner cavity of the dust suppression shell. The filter screen divides the inner cavity into a lower gravity settling chamber and an upper negative pressure adsorption chamber.

[0010] The air-guiding function unit is connected and disposed at the top of the negative pressure adsorption chamber;

[0011] The vibration cleaning function unit is located on the top of the dust suppression housing and includes a drive motor fixed to the dust suppression housing and an eccentric cam connected to the output end of the drive motor. The outer contour of the eccentric cam is in close contact with the filter screen frame.

[0012] The controller connects to and controls the operation of the conveying function unit, the air duct function unit, and the vibration cleaning function unit.

[0013] Furthermore, the comb-shaped flexible support strip is made of polyurethane rubber;

[0014] The conveying function unit also includes a servo motor and a weighing idler. The servo motor is connected to the shaft end of the drive roller via a flexible coupling, and the weighing idler is fixed to the conveyor frame below the upper branch of the annular conveyor belt.

[0015] Furthermore, the flexible coupling is a plum blossom-shaped flexible coupling, and the allowable axial deviation of the flexible coupling is ±2mm.

[0016] Furthermore, the frame of the filter screen is slidably connected to the inner wall of the dust suppression housing via a slide rail.

[0017] Furthermore, the induced draft function includes a centrifugal variable frequency induced draft fan connected to the top of the negative pressure adsorption chamber via a flange; a micro differential pressure sensor connected to the controller is fixed inside the negative pressure adsorption chamber, and the micro differential pressure sensor is a silicon resistive micro differential pressure sensor with a range of -1000Pa to +1000Pa.

[0018] Furthermore, the drive motor is a stepper motor, and the output shaft of the stepper motor extends through the top plate of the dust suppression housing into the negative pressure adsorption chamber, and is connected to the eccentric cam at its end by a key.

[0019] A control method for a needle-shaped fertilizer conveying device with a dust suppression and adsorption unit includes:

[0020] S1. Control and acquire the instantaneous mass of the material on the annular conveyor belt and the real-time running speed of the annular conveyor belt, and calculate the real-time material throughput;

[0021] S2. The controller calculates the theoretical dust generation based on the material throughput, the real-time operating speed, and the pre-calibrated breaking dust generation coefficient.

[0022] S3. Control the target rotation speed of the induced draft unit calculated based on the theoretical dust generation, and control the induced draft unit to operate at the target rotation speed; control the acquisition of the air pressure difference data before and after the filter screen, and calculate the growth slope of the air pressure difference;

[0023] S4. When the slope of the increase in air pressure difference is greater than the preset critical slope of adhesion, control the drive motor to rotate at a preset base frequency, drive the eccentric cam to periodically press down and release the frame of the filter screen.

[0024] S5. When the increase rate of the air pressure difference is less than or equal to the preset critical adhesion rate, maintain the current working state; during the vibration cleaning process, control and calculate the decrease rate of the air pressure difference.

[0025] S6. When the decrease in air pressure difference after three consecutive vibration cycles is less than the preset recovery threshold, control the drive motor to enter the frequency sweep operation mode, so that the speed of the drive motor changes continuously between the preset low frequency and the preset high frequency.

[0026] S7. When the decrease in air pressure difference after three consecutive vibration cycles is greater than or equal to the preset recovery threshold, control the drive motor to stop working;

[0027] S8. In the frequency sweep operation mode, when the air pressure difference recovers to the pre-calibrated initial reference value, the drive motor is controlled to stop working; the above steps are repeated.

[0028] Furthermore, the step of calculating the real-time material throughput includes: obtaining the material throughput based on the instantaneous mass and the real-time operating speed; the step of calculating the theoretical dust generation includes: obtaining the theoretical dust generation based on the material throughput, the real-time operating speed, and the break-off dust generation coefficient.

[0029] Furthermore, the step of calculating the growth slope of the pressure difference includes: obtaining the growth slope of the pressure difference based on the pressure difference values ​​of adjacent secondary samples and the sampling time interval.

[0030] Furthermore, in the frequency sweep operation mode, the rotational speed of the drive motor is controlled to change continuously to cover the frequency range between the preset low frequency and the preset high frequency.

[0031] The present invention has the following beneficial effects:

[0032] 1. This invention employs an array of comb-shaped flexible support strips distributed on the outer surface of a circular conveyor belt, with the spacing between the comb teeth matching the average length of the needle-shaped fertilizer. This design effectively accommodates and restricts the posture of the needle-shaped fertilizer, preventing the material from laterally rolling and squeezing against each other on the conveyor belt surface. This effectively reduces the physical breakage rate and dust generation of the needle-shaped fertilizer from the source, overcoming the defects of conventional flat belt conveyors that are prone to breakage and dust generation.

[0033] 2. This invention uses dynamic control based on air pressure difference. When the decrease in air pressure difference after three consecutive vibration cycles is less than the preset recovery threshold, the drive motor is controlled to enter the frequency sweep operation mode. By changing the rotation speed, the striking frequency of the eccentric cam coincides with the natural frequency of the local agglomeration area of ​​the filter screen, thereby exciting local resonance and effectively peeling off the agglomerates. This method solves the problem that hygroscopic fertilizer dust easily clogs the filter screen, enabling the system to have the ability to operate continuously without manual disassembly and cleaning. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0035] Figure 1 This is a schematic diagram of the overall external structure of the device;

[0036] Figure 2 This is a structural schematic diagram of the conveying function unit;

[0037] Figure 3 This is a schematic diagram of the internal structure of the dust suppression housing;

[0038] Figure 4 This is a flowchart of the method of the present invention.

[0039] In the diagram: 100, conveyor frame; 200, conveying function unit; 201, driving roller; 202, driven roller; 203, circular conveyor belt; 204, comb-shaped flexible support strip; 205, servo motor; 206, weighing idler roller; 207, flexible coupling; 300, dust suppression and adsorption function unit; 301, dust suppression housing; 302, filter screen; 303, gravity settling chamber; 304, negative pressure adsorption chamber; 305, slide rail; 400, induced draft function unit; 401, centrifugal variable frequency induced draft fan; 500, vibration cleaning function unit; 501, drive motor; 502, eccentric cam. Detailed Implementation

[0040] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0041] Example 1:

[0042] Combination Figure 1 As shown, the needle-shaped fertilizer conveying device with a dust suppression and adsorption device includes:

[0043] Conveyor frame 100;

[0044] Combination Figure 2 As shown, the conveying function unit 200 is provided on the conveyor frame 100 and includes a driving roller 201 and a driven roller 202 respectively fixed at both ends of the conveyor frame 100, and an annular conveyor belt 203 that is tensioned between the two rollers.

[0045] The outer surface of the annular conveyor belt 203 is provided with arrayed comb-shaped flexible support strips 204, the spacing of which is suitable for accommodating needle-shaped fertilizer to be conveyed;

[0046] Combination Figure 3 As shown, the dust suppression and adsorption functional unit 300 is located above the middle section of the conveyor frame 100. It includes a sealed dust suppression housing 301 fixed to the conveyor frame 100 and a filter screen 302 inclinedly arranged in the inner cavity of the dust suppression housing 301. The filter screen 302 divides the inner cavity into a lower gravity settling chamber 303 and an upper negative pressure adsorption chamber 304.

[0047] The air-expelling functional unit 400 is connected to the top of the negative pressure adsorption chamber 304;

[0048] The vibration cleaning function unit 500 is located on the top of the dust suppression housing 301 and includes a drive motor 501 fixed to the dust suppression housing 301 and an eccentric cam 502 connected to the output end of the drive motor 501. The outer contour of the eccentric cam 502 is in close contact with the frame of the filter screen 302.

[0049] The controller connects to and controls the operation of the conveying function unit 200, the air duct function unit 400, and the vibration cleaning function unit 500.

[0050] The conveyor frame 100 is a rectangular steel frame with a length of 3 to 8 meters, a width of 400 mm to 800 mm, and a height of 800 mm to 1400 mm to accommodate the height difference between the feeding end and the packaging end in the needle-shaped fertilizer production line. The drive roller 201 and the driven roller 202 are respectively installed at both ends of the conveyor frame 100, and the two together tension the annular conveyor belt 203, so that the annular conveyor belt 203 forms an upper conveying branch and a lower return branch. In this embodiment, needle-shaped fertilizer refers to strip-shaped or needle-shaped fertilizer particles with an aspect ratio exceeding a preset threshold. When conveyed on a regular flat belt, it is prone to lateral tumbling, mutual compression, and breakage, which in turn generates hygroscopic dust.

[0051] To reduce breakage at the source, the outer surface of the annular conveyor belt 203 is provided with an array of comb-shaped flexible support strips 204. The comb-shaped flexible support strips 204 are spaced apart along the conveying direction and form multiple limiting grooves in the transverse direction, so that the needle-shaped fertilizer remains aligned in the forward direction after entering the grooves. The dust suppression shell 301 is installed above the middle section of the conveyor frame 100 to cover the conveying area where dust is densely generated. The sealed structure is used to limit the airflow channel and reduce dust escape.

[0052] The filter screen 302 is inclinedly installed in the middle of the inner cavity of the dust suppression housing 301. Its lower side is the gravity settling chamber 303, and its upper side is the negative pressure adsorption chamber 304. When the dust-laden airflow flows from the gravity settling chamber 303 to the negative pressure adsorption chamber 304, particles with a diameter larger than the preset gravity settling threshold fall back under the action of gravity, while particles with a diameter smaller than or equal to the preset gravity settling threshold adhere to the surface of the filter screen 302. The preset gravity settling threshold is pre-calibrated based on the particle density of fertilizer dust and the average upward airflow velocity in the gravity settling chamber, calculated using Stokes' law to determine the critical point of balance between air resistance and gravity.

[0053] The air-guiding function unit 400 is arranged at the top of the negative pressure adsorption chamber 304, and forms an upward induced airflow inside the dust suppression housing 301 through suction. The vibration cleaning function unit 500 is installed at the top of the dust suppression housing 301, and the drive motor 501 outputs motion to the eccentric cam 502. The eccentric cam 502 is in close contact with the frame of the filter screen 302. The periodic displacement of the eccentric contour pushes the frame of the filter screen 302 to generate mechanical vibration, which is used to peel off the attached layer in time when the dust is still in a semi-adhesive state.

[0054] The controller receives relevant operating signals from the conveying function unit 200, the induced draft function unit 400, and the vibration cleaning function unit 500, and outputs control commands to the corresponding execution components, so that the conveying, adsorption, and cleaning actions are coordinated according to the set logic. This structural solution integrates material posture restriction, negative pressure adsorption, and filter screen vibration cleaning into the same equipment system, solving the problems of dust generation due to breakage and continuity of the filter structure due to hygroscopic dust clogging during the conveying of needle-shaped fertilizers.

[0055] The comb-shaped flexible support bar 204 is made of polyurethane rubber; the conveying function unit 200 also includes a servo motor 205 and a weighing idler 206. The servo motor 205 is connected to the shaft end of the drive roller 201 through a flexible coupling 207, and the weighing idler 206 is fixed on the conveyor frame 100 below the upper branch of the annular conveyor belt 203.

[0056] The comb-shaped flexible support strip 204 is made of polyurethane rubber. In this embodiment, polyurethane rubber combines elasticity, wear resistance, and hydrolysis resistance. Its hardness can be set to Shore 70 to 90 degrees so that the support strip can maintain the stability of the tooth shape and provide cushioning when the needle-shaped fertilizer comes into local contact. The support strip is preferably fixed to the outer surface of the annular conveyor belt 203 by hot vulcanization or adhesive bonding. The tooth height can be set to 10 mm to 30 mm, the tooth thickness can be set to 3 mm to 8 mm, and the comb tooth spacing is set to 80% to 120% of the average length of the needle-shaped fertilizer to achieve directional limiting without crushing the material.

[0057] The conveying function unit 200 also includes a servo motor 205 and a weighing idler 206. The servo motor 205 provides adjustable speed drive to the drive roller 201, which facilitates real-time adjustment of the conveyor belt running speed according to changes in output. The weighing idler 206 is located below the upper branch of the annular conveyor belt 203. The weighing idler 206 can integrate a strain gauge weighing sensor. The sensor output reflects the instantaneous mass of the material carried by the conveyor belt per unit time. The controller receives the real-time running speed feedback from the servo motor 205 and the instantaneous mass signal output from the weighing idler 206, and uses both as input parameters for subsequent throughput calculation and theoretical dust generation calculation.

[0058] By simultaneously setting the weighing roller 206 and the servo motor 205 in the conveying function unit 200, the two variables of material quantity and speed can participate in the control under the same time reference, avoiding insufficient or excessive suction caused by adjusting the suction based solely on the experience parameters of a single fan. The buffering and bearing effect of the polyurethane rubber bearing strip on needle-shaped fertilizer, combined with the above-mentioned real-time measurement function, allows the source breakage rate and the downstream air volume adjustment to be controlled simultaneously.

[0059] The flexible coupling 207 is a plum blossom-shaped flexible coupling 207, and the allowable axial deviation of the flexible coupling 207 is ±2mm;

[0060] The servo motor 205 and the drive roller 201 are connected by a plum blossom-shaped flexible coupling 207. The plum blossom-shaped flexible coupling 207 includes two metal claw discs and an elastic body disposed between the two claw discs. The elastic body can be made of polyurethane material to absorb the impact and minor installation errors during the transmission process. The allowable axial deviation of the coupling is set to ±2mm. The significance of this is that when the conveyor frame 100 undergoes minor axial displacement due to load, temperature or installation tolerance during long-term operation, the output shaft of the servo motor 205 and the shaft of the drive roller 201 can still maintain stable transmission, and the additional load on the bearings will not increase due to rigid off-center loading.

[0061] Needle fertilizer conveying equipment is prone to acceleration and deceleration shocks during variable speed operation. If a rigid coupling is used, the motor torque fluctuations will be directly transmitted to the drive roller 201 and the conveyor belt, thereby aggravating local material jumping. In this embodiment, the plum blossom-shaped flexible coupling 207 has a buffering effect on torque pulsation, which can reduce the amplitude of conveyor belt speed fluctuations and make the directional bearing of needle fertilizer by the comb-shaped flexible bearing strip 204 more stable. When the controller adjusts the speed of the servo motor 205 according to the production rhythm, the coupling maintains reliable transmission within a range of ±2mm axial deviation, which helps to ensure the consistency between the real-time operating speed measurement value and the actual conveying speed, and improves the accuracy of subsequent theoretical dust generation calculation.

[0062] The frame of the filter screen 302 is slidably connected to the inner wall of the dust suppression housing 301 via the slide rail 305;

[0063] The filter screen 302 includes a mesh surface and a frame. The outer periphery of the frame is slidably connected to the inner wall of the dust suppression housing 301 via a slide rail 305. In this embodiment, the slide rail 305 is used to limit the displacement direction and displacement range of the frame of the filter screen 302, so that the filter screen 302 can generate a small reciprocating displacement along a predetermined trajectory during vibration cleaning, without disorderly swaying. The slide rail 305 can be implemented in the form of a linear guide rail, a guide groove with a slider, or a wear-resistant bushing with a guide post. Preferably, a combination of a corrosion-resistant metal guide rail and a polymer wear-resistant slider is used to adapt to the hygroscopic and slightly corrosive characteristics of fertilizer dust.

[0064] The movable gap of the filter screen 302 frame in the slide rail 305 can be set from 0.5mm to 3mm, and the displacement stroke can be set from 1mm to 6mm. This parameter range can balance the dynamic transmission efficiency and structural stability. In order to ensure that the frame does not detach from the cam under sweep frequency vibration and tilted arrangement, a reset elastic element is also connected between the frame of the filter screen 302 and the inner wall of the dust suppression housing 301 or the slide rail 305. The reset elastic element provides a preload force towards the eccentric cam 502 to ensure that the frame of the filter screen 302 can quickly retract under continuous high frequency reciprocating vibration and always maintain close contact with the outer contour of the eccentric cam 502.

[0065] When the filter screen 302 is arranged at an angle, larger particles slide down the screen surface under the action of gravity and enter the bottom of the gravity settling chamber 303, while fine dust adheres to the surface of the screen. When the eccentric cam 502 presses against the frame of the filter screen 302, the frame generates repeatable reciprocating vibration by means of the guide rail 305. The vibration acceleration acts on the attached dust, causing the dust layer in a semi-adhesive state to detach from the screen surface and fall back.

[0066] If the filter screen 302 frame and the dust suppression housing 301 are fixedly connected, the displacement of the eccentric cam 502 will be difficult to convert into controllable vibration of the entire filter screen, and the cleaning effect will be lower than the expected qualified cleaning threshold. Setting the filter screen 302 frame as a sliding connection can make the mechanical displacement output by the vibration cleaning function unit 500 effectively act on the filter screen 302 body, and provide the necessary structural freedom for local resonance during subsequent frequency sweep operation.

[0067] The induced draft function unit 400 includes a centrifugal variable frequency induced draft fan 401 with a flange connected to the top of the negative pressure adsorption chamber 304; a micro differential pressure sensor connected to the controller is fixed inside the negative pressure adsorption chamber 304, and the micro differential pressure sensor is a silicon resistive micro differential pressure sensor with a range of -1000Pa to +1000Pa.

[0068] The induced draft unit 400 uses a centrifugal variable frequency induced draft fan 401. The induced draft fan is fixed to the top of the negative pressure adsorption chamber 304 via a flange. The flange connection is used to ensure the sealing and disassembly of the connection. The centrifugal variable frequency induced draft fan 401 can be selected as a model with a rated power of 3000W. The speed adjustment range can be set to 30% to 100% of the rated speed, which is used to adjust the induced air volume according to the theoretical dust generation. Compared with a fixed frequency fan, the variable frequency induced draft fan can continuously change the suction capacity according to the target speed output by the controller, reducing the situation where qualified needle-like particles are carried away due to excessive suction.

[0069] A micro-pressure differential sensor is fixedly installed inside the negative pressure adsorption chamber 304. The micro-pressure differential sensor is a silicon resistive micro-pressure differential sensor with a range of -1000Pa to +1000Pa. In this embodiment, the silicon resistive micro-pressure differential sensor is used to continuously detect the pressure difference before and after the filter screen 302. Its output signal reflects the degree of dust accumulation on the surface of the filter screen 302 and the moisture absorption and adhesion process. The micro-pressure differential sensor is fixed in the stable airflow area of ​​the negative pressure adsorption chamber 304 and is connected to the spaces on both sides of the filter screen 302 through pressure guiding channels to reduce the interference of local eddies on the measurement results.

[0070] The controller reads data from the micro differential pressure sensor according to a set sampling period, which can be set from 0.1s to 2s. Since needle-shaped fertilizer dust has hygroscopic properties, simply using a fixed differential pressure value as the cleaning timing will result in a lag. Therefore, this embodiment uses the trend of differential pressure change as the basis for judgment. Relying on a micro differential pressure sensor with a range of -1000Pa to +1000Pa, it can cover the range of differential pressure changes during normal adsorption, dust accumulation, and cleaning recovery processes, providing a stable data basis for subsequent growth slope calculation.

[0071] In this embodiment, the air pressure difference data before and after the filter screen 302 refers to the relative pressure difference between the space pressure on the dust-facing side and the space pressure on the dust-repelling side of the filter screen 302. The physical meaning of this data is to characterize the resistance state formed by the filter screen 302 to the airflow. When the filter screen 302 is not covered with dust or the amount of dust is less than the reference threshold, the air pressure difference is within the basic pressure range and the fluctuation amplitude is less than the preset fluctuation threshold. When dust adhesion, moisture absorption and pore blockage intensify, the air pressure difference increases accordingly.

[0072] Among them, the reference threshold and the preset fluctuation threshold are calibrated based on the historical data of differential pressure fluctuation obtained by the equipment under multiple independent operations under no-load and standard load conditions; in order to ensure that the subsequent control logic has a consistent judgment benchmark, the controller can record a set of reference differential pressure data under the stable exhaust state after the equipment is under no-load or after the filter screen 302 has been cleaned once, and use the set of reference differential pressure data as the comparison starting point for subsequent judgment of the resistance change of the filter screen 302.

[0073] The raw signal output by the micro differential pressure sensor can first be converted from analog to digital, and then the controller performs amplitude limiting and short-term smoothing. Amplitude limiting is used to eliminate abnormal peak values ​​caused by instantaneous vibration of the pressure guide tube or electromagnetic interference. Short-term smoothing is used to preserve the overall trend of differential pressure change without excessively weakening the actual changes before and after the cleaning action. The processed differential pressure data is transmitted to the differential pressure growth slope calculation step on the one hand, and used for comparison of differential pressure recovery state after vibration cleaning on the other hand. Thus, the sensor signal can simultaneously serve as two logical inputs for blockage trend identification and cleaning effect confirmation.

[0074] The drive motor 501 is a stepper motor. The output shaft of the stepper motor passes through the top plate of the dust suppression housing 301 and extends into the negative pressure adsorption chamber 304, and is connected to the eccentric cam 502 at the end by a key.

[0075] The drive motor 501 is a stepper motor, which is mounted on a motor mount on the outside of the top plate of the dust suppression housing 301. Its output shaft passes through the top plate of the dust suppression housing 301 and extends into the negative pressure adsorption chamber 304. A seal is provided at the part of the output shaft that passes through the plate to reduce the entry of outside air into the negative pressure adsorption chamber 304 through the shaft hole, which would affect the suction stability. The end of the stepper motor output shaft is connected to the eccentric cam 502 by a key connection. The key connection is used to reliably transmit torque and prevent the eccentric cam 502 from slipping relative to each other during high-frequency speed change.

[0076] The selection of stepper motors is based on their rotation angle control accuracy, which meets the set step angle accuracy. This allows the controller to output pulse signals according to the set basic frequency and sweep frequency law, so that the eccentric cam 502 rotates at a predetermined angular velocity. The outer contour of the eccentric cam 502 is in close contact with the frame of the filter screen 302. When the eccentric cam 502 rotates, its radius change is converted into periodic pushing and releasing on the frame, forming an approximately simple harmonic mechanical excitation.

[0077] The basic operating frequency of the stepper motor can be set from 5Hz to 50Hz, and the sweep frequency range can be set from 10Hz to 150Hz. The specific range can be set according to the quality of the filter screen 302 frame, the stiffness of the screen surface, and the clearance of the slide rail 305. Using a stepper motor instead of an ordinary asynchronous motor is beneficial to quickly change the speed according to the pressure difference recovery during the cleaning process, realizing the switching between two modes of fixed frequency vibration and continuous frequency change, thereby meeting the cleaning requirements of two different adhesion states: semi-adhesive dust and highly adhesive agglomerates.

[0078] Example 2:

[0079] Combination Figure 4 As shown, the control method for a needle-shaped fertilizer conveying device with a dust suppression and adsorption device includes:

[0080] S1. Control and acquire the instantaneous mass of the material on the annular conveyor belt 203 and the real-time running speed of the annular conveyor belt 203, and calculate the real-time material throughput.

[0081] S2. The control calculates the theoretical dust generation based on the material throughput, real-time operating speed, and pre-calibrated breaking dust generation coefficient.

[0082] S3. Control the target rotation speed of the induced draft fan 400 calculated based on the theoretical dust generation, and control the induced draft fan 400 to operate at the target rotation speed; control the acquisition of the air pressure difference data before and after the filter screen 302, and calculate the growth slope of the air pressure difference.

[0083] S4. When the slope of the increase in air pressure difference is greater than the preset critical slope of adhesion, control the drive motor 501 to rotate at the preset basic frequency, drive the eccentric cam 502 to periodically press down and release the frame of the filter screen 302.

[0084] S5. When the slope of the increase in air pressure difference is less than or equal to the preset critical adhesion slope, maintain the current working state; during the vibration cleaning process, control the decrease in the calculated air pressure difference.

[0085] S6. When the decrease in air pressure difference after three consecutive vibration cycles is less than the preset recovery threshold, control the drive motor 501 to enter the frequency sweep operation mode, so that the speed of the drive motor 501 changes continuously between the preset low frequency and the preset high frequency.

[0086] S7. When the decrease in air pressure difference after three consecutive vibration cycles is greater than or equal to the preset recovery threshold, control the drive motor 501 to stop working.

[0087] S8. In the frequency sweep operation mode, when the air pressure difference recovers to the pre-calibrated initial reference value, control the drive motor 501 to stop working; repeat the above steps cyclically.

[0088] The control method is executed by a controller, which can be an industrial programmable controller or an embedded control unit with an analog-to-digital data acquisition interface. The controller obtains the instantaneous mass signal of the material on the annular conveyor belt 203 from the weighing idler roller 206, obtains the real-time running speed signal of the annular conveyor belt 203 from the encoder of the servo motor 205, and calculates the real-time material throughput under a uniform sampling period. The pre-calibrated dust generation coefficient is determined by experiment. During the experiment, the actual dust production per unit time is collected under different material throughput and different belt speed conditions. Based on the statistical results, the coefficient value corresponding to the specific needle-shaped fertilizer type, the bearing strip structure, and the equipment size is obtained.

[0089] The controller calculates the theoretical dust generation based on the material throughput, real-time operating speed, and breaking dust generation coefficient. Then, it converts the theoretical dust generation into the target rotational speed of the induced draft unit 400 based on the correspondence between the theoretical dust generation and the target induced air volume. This correspondence can be established through the fan performance curve and the wind speed distribution test inside the dust suppression housing 301 to ensure that the wind speed on the windward side of the filter screen 302 is sufficient to remove dust without removing qualified fertilizer particles. The controller continuously acquires the air pressure difference data before and after the filter screen 302 and calculates the growth slope based on the pressure difference changes at adjacent times.

[0090] The preset adhesion critical slope is obtained through calibration. Its physical meaning is the limit of the pressure difference growth rate when the dust on the surface of the filter screen 302 changes from a loose adsorbed state to a hygroscopic semi-adhesive state. When the pressure difference growth slope is greater than this limit, the controller determines that the dust has entered a stage suitable for early peeling. It controls the stepper motor to run at the basic frequency, driving the eccentric cam 502 to periodically act on the frame of the filter screen 302, causing the filter screen 302 to vibrate back and forth. During the vibration cleaning process, the controller records the pressure difference decrease according to the vibration cycle. If the pressure difference decrease is less than the preset recovery threshold after three consecutive vibration cycles, it indicates that the conventional vibration has not fully removed the local agglomerates. The controller switches the stepper motor to the frequency sweep operation mode, so that its speed changes continuously between the preset low frequency and the preset high frequency.

[0091] If the pressure difference decreases to or exceeds the preset recovery threshold after three consecutive vibration cycles, the controller determines that the air permeability of the filter 302 has recovered to an acceptable level and controls the stepper motor to stop working. When in the sweep frequency operation mode, the controller continues to monitor the air pressure difference and stops the stepper motor after the air pressure difference recovers to the initial reference value. The above steps are executed cyclically, so that conveying, suction and cleaning are carried out continuously in the production process without relying on manual disassembly and washing or stopping the machine to knock. In this embodiment, the above control process is executed according to a clear data flow sequence: the controller receives the instantaneous mass signal output by the weighing roller 206 and the real-time running speed signal output by the encoder of the servo motor 205 at the same sampling time.

[0092] The controller performs time alignment on the two signals to avoid throughput calculation deviations caused by the quality data and speed data coming from different time slices. The controller adds a microsecond-level timestamp to each received instantaneous quality signal and real-time running speed signal. When the difference between the timestamps of the two signals is less than the set tolerance threshold, they are determined to be data from the same time slice. If the difference is greater than the tolerance threshold, a linear interpolation algorithm is used to resample the signal with the higher sampling frequency to match the time reference of the other signal.

[0093] The controller calculates the real-time material throughput based on the time-aligned data and sends the result to the theoretical dust generation calculation step. After obtaining the theoretical dust generation, the controller searches for the target speed range that matches the current theoretical dust generation in the pre-stored fan speed classification table or corresponding relationship table, and then outputs the corresponding speed command to the variable frequency induced draft fan. After the induced draft fan is running stably, the controller continues to receive the air pressure difference data from the micro differential pressure sensor according to the set sampling period and forms a continuous time series. The controller then judges whether the growth trend of the air pressure difference reaches the adhesion warning level based on the continuous time series, and thus decides whether to start vibration cleaning.

[0094] The preset adhesion critical slope, preset recovery threshold, and initial reference value all have clear physical meanings and determination methods. The preset adhesion critical slope is used to characterize the dividing point where the resistance of the filter screen 302 changes from a slow increase to a non-linear accelerated increase. Its determination method can be as follows: under the same ambient humidity or typical ambient humidity conditions, record the pressure difference change curve of the filter screen 302 from a clean state to a semi-adhesive state, and select the pressure difference growth rate corresponding to the start of a continuous adhesion layer on the screen surface as a calibration reference.

[0095] The average value or safety correction value is then combined with the results of multiple tests and written into the controller parameter area. The preset recovery threshold is used to characterize whether the resistance of the filter screen 302 has recovered sufficiently after a vibration cleaning. The judgment object is not the absolute pressure difference, but the effective degree of pressure difference drop within three consecutive vibration cycles. When the drop reaches the preset recovery threshold, it means that the basic frequency vibration is sufficient to peel off the current attached layer, and the drive motor 501 can be stopped to avoid unnecessary continuous knocking.

[0096] The initial reference value is used to characterize the reference differential pressure level of the filter screen 302 when it returns to a stable ventilation state at the beginning of this round of conveying operation or after the last cleaning. The controller can continuously collect multiple sets of differential pressure data when the induced draft fan speed is stable, the conveying state is stable, and the filter screen 302 is confirmed to be clean or restored, and take the average value as the initial reference value to reduce misjudgment caused by single sampling fluctuations.

[0097] The judgment process for the vibration cleaning stage is also carried out in sequence: After the drive motor 501 is started, the controller records the current pressure difference at the end of each cycle in units of vibration cycle, and compares it with the reference pressure difference before the start of vibration to obtain the pressure difference drop effect generated in that cycle; after three consecutive cycles, the controller combines the drop situation of these three cycles for judgment, instead of drawing conclusions based solely on the instantaneous change of a single cycle, in order to reduce the probability of false triggering caused by occasional dust shedding or local airflow disturbance; the specific method of combining the judgment is as follows: calculate the average pressure difference at the end of these three vibration cycles, and subtract this average from the reference pressure difference before the start of vibration, and the absolute value of the difference is the decrease in air pressure difference;

[0098] If the judgment result is that the decrease is less than the preset recovery threshold, i.e., the recovery is insufficient, the controller switches to output a sweep frequency control command to the stepper motor; if the judgment result is that the recovery is sufficient, the controller stops the stepper motor and keeps the induced draft fan working. Through the above-mentioned phased and data source-based processing sequence, a clear causal connection is formed between the material conveying status, dust generation prediction results, ventilation adjustment actions, blockage trend identification results, and vibration cleaning actions, thereby avoiding the control method becoming a closed-loop unknown calculation process that only gives the result without explaining the intermediate processing.

[0099] The steps for calculating real-time material throughput include: obtaining material throughput based on instantaneous mass and real-time operating speed; the steps for calculating theoretical dust generation include: obtaining theoretical dust generation based on material throughput, real-time operating speed, and break-off dust generation coefficient.

[0100] In this embodiment, the real-time material throughput represents the mass of needle-shaped fertilizer conveyed by the circular conveyor belt 203 per unit time. The controller multiplies the instantaneous mass value measured by the weighing idler 206 with the real-time operating speed value fed back by the servo motor 205 to obtain the material throughput. Considering the consistency of physical dimensions, the weighing idler 206 has a fixed effective weighing section length in its structure. When processing, the controller first divides the measured instantaneous mass by the effective weighing section length to convert it into a unit length load, and then multiplies the unit length load by the real-time operating speed to accurately calculate the real-time material throughput. The mathematical formula is as follows:

[0101]

[0102] In the formula, This represents the real-time material throughput, measured in kg / s. It represents the measured instantaneous mass, with the dimension of kg; This indicates the effective weighing section length of the weighing idler roller 206, in meters. The real-time operating speed is expressed in m / s. If the weighing idler 206 outputs a load per unit length, the controller obtains the conveyed mass per unit time by multiplying the load per unit length by the conveying speed. The result is consistent with the meaning of the above calculation.

[0103] The theoretical dust generation is calculated by multiplying the material throughput by the square of the real-time operating speed and then by the breaking dust generation coefficient. This is based on the fact that the probability of needle-shaped fertilizer colliding and breaking during transport is related not only to the total transport volume but also to the impact intensity caused by the speed. The square of the real-time operating speed reflects the increasing trend of collision energy as speed increases, and the breaking dust generation coefficient characterizes the sensitivity of dust generation under a specific combination of materials and equipment. The mathematical expression for this calculation is:

[0104]

[0105] In the formula, This represents the theoretical dust generation, with dimensions in kg / s. This represents the material throughput, measured in kg / s. This indicates the real-time operating speed, measured in m / s. The breaking-off dust generation coefficient is used to ensure the consistency of physical dimensions on both sides of the equation. The dimension of the quantity is clearly defined as s² / m²; the dust generation coefficient can be calibrated in the following way: the equipment is run under several belt speeds and several load conditions, the dust mass intercepted by the filter screen 302 within the same time period is collected, the influence of environmental dust is removed, and the coefficient value is obtained by regression. The coefficient value can be stored in the controller parameter area.

[0106] To verify whether the theoretical basis of this coefficient is sufficient, a comparative experiment can be conducted: after calibration, a set of verification conditions different from the calibration conditions are set, the actual dust mass collected under the verification conditions is recorded, and compared with the theoretical dust generation amount calculated based on this breakage dust generation coefficient.

[0107] If the relative error between the two is within ±10%, it proves that the coefficient and the square of the velocity can truly reflect the nonlinear effect of collision energy on dust generation, and the experimental data is sufficient to support the accuracy of the theoretical dust generation calculation. After the controller calculates the theoretical dust generation according to the above formula, it maps the result to the target speed of the induced draft fan. Using this calculation method can establish a quantitative correspondence between air volume adjustment and actual conveying state, avoiding the problem that traditional fixed air volume settings cannot take into account both low-load and high-load conditions.

[0108] The above calculation process of theoretical dust generation logically constitutes a dynamic dust generation assessment model. The purpose of this dynamic dust generation assessment model is to quantitatively estimate the theoretical dust generation caused by material breakage during the conveying process when the instantaneous dust generation cannot be directly measured. Logically, the model includes an input layer, a computation layer, and an output layer. The input layer receives real-time material throughput and real-time operating speed as input variables. The computation layer combines the pre-calibrated breakage dust generation coefficient as a system parameter, calculates the collision energy factor through the square of the speed, multiplies it by the material throughput and the breakage dust generation coefficient, and finally outputs the theoretical dust generation.

[0109] The model as a whole characterizes the complete physical dust generation process of needle-shaped fertilizer breaking on the conveyor belt due to acceleration and deceleration impacts, material squeezing and collisions, and friction with the carrier strip, releasing dust under induced airflow, and its quantitative causal relationship with the motion state. Since the square of the material's velocity directly corresponds to the change in kinetic energy, the model based on this can truly reflect the nonlinear influence of collision energy on dust generation.

[0110] The steps for calculating the growth slope of the pressure difference include: obtaining the growth slope of the pressure difference based on the pressure difference values ​​of two adjacent samples and the sampling time interval;

[0111] Since the real-time variable frequency speed regulation of the induced draft fan will directly cause the system's basic air pressure difference to fluctuate beyond the preset fluctuation threshold, in order to avoid misjudging the increase in pressure difference caused by the increase in air volume as dust adhesion, when processing the air pressure difference signal, the controller calls the pre-stored wind speed-wind resistance characteristic curve according to the current real-time speed or target speed of the induced draft fan, performs wind speed compensation normalization processing on the actual air pressure difference value read, eliminates the additional pressure difference variable caused by the change in fan speed, and obtains the equivalent air pressure difference that reflects pure dust resistance;

[0112] The controller reads the air pressure difference signal on both sides of the filter 302 from the micro differential pressure sensor according to a predetermined sampling period, subtracts the air pressure difference value at the previous sampling time from the air pressure difference value at the current sampling time, and divides it by the time interval between the two sampling times to obtain the current air pressure difference growth slope. In terms of data flow and interaction, the analog voltage or current signal output by the micro differential pressure sensor is transmitted to the analog input module of the controller through a shielded cable and converted into a digital quantity by a 16-bit analog-to-digital converter.

[0113] The micro differential pressure sensor directly sends digital differential pressure data containing a checksum to the controller via the recommended standard 485 communication interface and the Modebs-Remote Terminal Unit protocol, thereby ensuring the anti-interference capability and clear interaction of the data transmission process. The sampling time interval can be set to 0.1s, 0.5s, or 1s, preferably selected in combination with the fan response time and dust adhesion rate to balance dynamic sensitivity and noise immunity. If there are random fluctuations in the output of the micro differential pressure sensor, the controller can perform a moving average processing on several consecutive sampled values ​​before difference calculation. The averaging window can be set to 3 to 10 points to reduce the impact of local disturbances on slope judgment.

[0114] In this embodiment, the pressure difference growth slope is used to describe the rate at which the resistance of the filter screen 302 increases per unit time. For hygroscopic fertilizer dust, the pressure difference change on the surface of the filter screen 302 is affected not only by the total amount of dust accumulation but also by the increased adhesion of the dust after absorbing moisture. When the dust changes from a loose state to a semi-adhesive state, the local pores of the filter screen 302 are quickly blocked, and the pressure difference growth rate will increase in a short time. Therefore, by calculating the slope by subtracting two adjacent sampling values, the clogging trend can be identified in advance before reaching the clogging critical value. The controller compares this slope with the preset adhesion critical slope, and the comparison result directly determines whether to activate the vibration cleaning function unit 500. Therefore, this calculation step has a clear data transmission relationship with the subsequent execution action and is not an isolated measurement.

[0115] The calculation and comparison process of the pressure difference growth slope logically constitutes a pressure difference trend early warning model. The purpose of this pressure difference trend early warning model is to identify the deteriorating trend of dust changing from a loose state to a hygroscopic semi-adhesive state in advance before the dust completely clogs the filter screen 302, thereby grasping the best cleaning time. Logically, the model receives the pressure difference sampling value and sampling time interval in a continuous time series as input, calculates the pressure difference growth slope through differential calculation, compares the slope with the preset adhesion critical slope as a reference, and finally outputs a trigger command to start vibration cleaning.

[0116] The model as a whole characterizes the physical process and dynamic evolution law of the nonlinear acceleration of airflow resistance as hygroscopic dust accumulates on the surface of filter screen 302, with the decrease of porosity and the formation of liquid bridge force between dust particles. Because the adhesion force of dust increases sharply after absorbing moisture, it will quickly block the pores. Therefore, by monitoring the slope model, the phenomenon of drastic change in overall pressure difference due to the blockage of micropores can be accurately mapped.

[0117] In the frequency sweep operation mode, the speed of the drive motor 501 is continuously changed to cover the frequency range between the preset low frequency and the preset high frequency.

[0118] When the pressure difference drops below the preset recovery threshold after three consecutive vibration cycles, the controller determines that there may be agglomerated areas with high adhesion in the filter screen 302, and the normal base frequency vibration is insufficient to remove them; at this time, the stepper motor enters the frequency sweep operation mode, and the controller outputs a pulse sequence with continuously changing frequency to the stepper motor, so that the striking frequency of the eccentric cam 502 changes between the preset low frequency and the preset high frequency.

[0119] The preset low frequency can be set to 10Hz to 20Hz, the preset high frequency can be set to 80Hz to 150Hz, and the frequency sweep period can be set to 5s to 30s. The filter screen 302 frame, screen surface, attached dust agglomerates, and slide rail 305 constraint together constitute a local vibration system. Different agglomerate positions and sizes correspond to different local natural frequencies. The controller does not need to pre-quantitatively identify the natural frequency of each agglomerate, but instead uses continuous frequency scanning to make the mechanical excitation output by the eccentric cam 502 cover the set frequency band. When the tapping frequency is close to the natural frequency of a certain local agglomerate area, the vibration amplitude of that area increases, and the adhesion interface between the agglomerate and the filter screen 302 bears higher peeling stress, thereby causing the highly adhesive agglomerate to detach from the screen surface.

[0120] Compared to fixed-frequency tapping, this method concentrates mechanical energy on the sensitive area, reducing the number of ineffective taps. During the frequency sweep, the controller continuously monitors the air pressure difference. When the air pressure difference returns to the pre-calibrated initial reference value, it indicates that the overall air permeability of the filter 302 has returned to the initial cleaning level. The controller then stops the stepper motor and ends the frequency sweep cleaning. This method relies on the adjustable speed characteristics of the stepper motor, the mechanical excitation characteristics of the eccentric cam 502, and the sliding frame structure of the filter 302 to treat highly adhesive agglomerates formed after the hardening of hygroscopic fertilizer dust.

[0121] The striking frequency coincides with the natural frequency of the local agglomeration area. In this embodiment, it means that the periodic mechanical excitation frequency applied by the eccentric cam 502 to the frame of the filter screen 302 enters the high response frequency band of a certain local agglomeration area, causing the vibration displacement or vibration acceleration of the area to exceed the response level under the mismatched frequency and form resonance enhancement. Its physical meaning is not that the controller directly measures the quantitative evaluation value of the natural frequency of the agglomeration, but that the excitation frequency is gradually passed through multiple candidate frequency bands by using a frequency scanning method. As long as a certain frequency band matches the response characteristics of the local vibration system, a resonance enhancement effect can be formed in that local area.

[0122] The frequency sweep operation mode can be executed in the following order: The controller first sets the stepper motor to a preset low-frequency starting point, so that the filter screen 302 enters a low-energy trial vibration state; the controller gradually increases the stepper motor speed according to a preset step size or continuous acceleration method, so that the eccentric cam 502 strikes multiple response intervals in the range from low frequency to high frequency; during the frequency rise, the controller continuously reads the data of the micro differential pressure sensor. If it finds that the differential pressure drops continuously in a certain frequency band, it maintains the operation of that frequency band for a short time so that the activated local agglomerates can be fully peeled off.

[0123] If the differential pressure does not decrease, the frequency sweep continues to a higher frequency band. After reaching the preset high frequency, the controller can directly stop the frequency sweep or return to the preset low frequency to start the next round of scanning until the differential pressure recovers to the initial reference value. The above processing method forms a closed-loop relationship between the frequency sweep action and the differential pressure feedback. The frequency sweep provides mechanical excitation covering different local natural frequencies, and the differential pressure feedback is used to confirm whether the mechanical excitation has been converted into the recovery of the ventilation capacity of the filter 302.

[0124] To avoid misjudging transient, occasional disturbances as effective resonant cleanup, the controller can use a continuous decrease in differential pressure and its maintenance for at least one set observation period as a criterion for effective frequency sweep. Only when the differential pressure maintains a downward trend during the observation period is the current frequency band considered to have effectively stripped local agglomerates. Through the above explanation, the triggering conditions, scanning logic, feedback judgment path, and stopping conditions of local resonance all have clear input sources and action destinations, thus making the control process of frequency sweeping agglomerate stripping clearly public. The interaction process between the frequency sweeping excitation and the mesh response logically constitutes a local resonance stripping model.

[0125] The purpose of this local resonance stripping model is to automatically find and amplify the vibration response of local agglomeration areas through broadband mechanical excitation without prior quantitative assessment of the agglomeration location and mass distribution, thereby achieving precise stripping of highly adhesive agglomerates. The model's logical structure includes three stages: excitation input, system response, and effect feedback. It receives the sweeping speed sequence of the drive motor 501 as excitation input and converts it into the mechanical excitation frequency of the eccentric cam 502. Using the local natural frequencies of each region of the filter 302 caused by agglomeration as implicit parameters, it outputs the vibration acceleration of each region. Finally, it uses the air pressure difference recovery value as effect feedback to close the loop and control the sweeping frequency action.

[0126] The model as a whole characterizes the phenomenon of energy accumulation and amplitude amplification that occurs when mechanical waves propagate on a tensioned mesh surface with a non-uniform mass distribution and the excitation frequency matches the natural frequency of the local mass-stiffness system. It also describes the complete physical and mechanical process by which the resulting peak peel stress overcomes the dust adhesion force. Because the resonance amplifies the local mechanical stress, it can effectively break up hardened hygroscopic dust clumps.

[0127] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A needle-shaped fertilizer delivery device with dust suppression adsorption means, characterized in that, include: Conveyor frame (100); The conveying function unit (200) is provided on the conveyor frame (100) and includes a drive roller (201) and a driven roller (202) respectively fixed at both ends of the conveyor frame (100), and an annular conveyor belt (203) that is tensioned between the two rollers. The outer surface of the annular conveyor belt (203) is provided with arrayed comb-shaped flexible support strips (204), the spacing of which is suitable for accommodating needle-shaped fertilizer to be conveyed; The dust suppression and adsorption function unit (300) is located above the middle section of the conveyor frame (100), and includes a sealed dust suppression shell (301) fixed to the conveyor frame (100) and a filter screen (302) inclinedly arranged in the inner cavity of the dust suppression shell (301). The filter screen (302) divides the inner cavity into a lower gravity settling chamber (303) and an upper negative pressure adsorption chamber (304). An air-guiding function unit (400) is connected to the top of the negative pressure adsorption chamber (304); The vibration cleaning function unit (500) is located on the top of the dust suppression housing (301) and includes a drive motor (501) fixed to the dust suppression housing (301) and an eccentric cam (502) connected to the output end of the drive motor (501). The outer contour of the eccentric cam (502) is in close contact with the frame of the filter screen (302). The controller connects to and controls the operation of the conveying function unit (200), the air duct function unit (400), and the vibration cleaning function unit (500).

2. The needle-shaped fertilizer delivery device with dust suppression adsorption device according to claim 1, characterized in that, The comb-shaped flexible support strip (204) is made of polyurethane rubber; the conveying function unit (200) also includes a servo motor (205) and a weighing idler (206). The servo motor (205) is connected to the shaft end of the drive roller (201) through an elastic coupling (207), and the weighing idler (206) is fixed on the conveyor frame (100) below the upper branch of the annular conveyor belt (203).

3. The needle-shaped fertilizer delivery device with dust suppression adsorption device according to claim 2, characterized in that, The flexible coupling (207) is a plum blossom-shaped flexible coupling (207), and the allowable axial deviation of the flexible coupling (207) is ±2mm.

4. The needle-shaped fertilizer delivery device with dust suppression adsorption device according to claim 1, characterized in that, The frame of the filter screen (302) is slidably connected to the inner wall of the dust suppression housing (301) via a slide rail (305).

5. The needle-shaped fertilizer conveying device with dust suppression and adsorption device according to claim 1, characterized in that, The induced draft function (400) includes a centrifugal variable frequency induced draft fan (401) with a flange connected to the top of the negative pressure adsorption chamber (304); a micro differential pressure sensor connected to the controller is fixed inside the negative pressure adsorption chamber (304), and the micro differential pressure sensor is a silicon resistive micro differential pressure sensor with a range of -1000Pa to +1000Pa.

6. The needle-shaped fertilizer conveying device with dust suppression and adsorption device according to claim 1, characterized in that, The drive motor (501) is a stepper motor. The output shaft of the stepper motor passes through the top plate of the dust suppression housing (301) and extends into the negative pressure adsorption chamber (304), and is connected to the eccentric cam (502) at the end by a key.

7. A control method for a needle-shaped fertilizer conveying device with a dust suppression and adsorption device, applied to the needle-shaped fertilizer conveying device with a dust suppression and adsorption device as described in any one of claims 1 to 6, characterized in that, include: S1. Control the instantaneous mass of the material on the annular conveyor belt (203) and the real-time running speed of the annular conveyor belt (203), and calculate the real-time material throughput; S2. The controller calculates the theoretical dust generation based on the material throughput, the real-time operating speed, and the pre-calibrated breaking dust generation coefficient. S3. Control the target rotation speed of the induced draft function unit (400) calculated based on the theoretical dust generation, and control the induced draft function unit (400) to operate at the target rotation speed; control the acquisition of the air pressure difference data before and after the filter screen (302), and calculate the growth slope of the air pressure difference; S4. When the slope of the increase of the air pressure difference is greater than the preset critical slope of adhesion, control the drive motor (501) to rotate at the preset basic frequency, drive the eccentric cam (502) to periodically press down and release the frame of the filter screen (302); S5. When the increase rate of the air pressure difference is less than or equal to the preset critical adhesion rate, maintain the current working state; during the vibration cleaning process, control and calculate the decrease rate of the air pressure difference. S6. When the decrease in air pressure difference after three consecutive vibration cycles is less than the preset recovery threshold, the drive motor (501) is controlled to enter the frequency sweep operation mode, so that the speed of the drive motor (501) changes continuously between the preset low frequency and the preset high frequency. S7. When the decrease in air pressure difference after three consecutive vibration cycles is greater than or equal to the preset recovery threshold, control the drive motor (501) to stop working. S8. In the frequency sweep operation mode, when the air pressure difference recovers to the pre-calibrated initial reference value, the drive motor (501) is controlled to stop working; the above steps are executed repeatedly.

8. The control method according to claim 7, characterized in that, The steps for calculating the real-time material throughput include: obtaining the material throughput based on the instantaneous mass and the real-time operating speed; the steps for calculating the theoretical dust generation include: obtaining the theoretical dust generation based on the material throughput, the real-time operating speed, and the break-off dust generation coefficient.

9. The control method according to claim 7, characterized in that, The steps for calculating the growth slope of the pressure difference include: obtaining the growth slope of the pressure difference based on the pressure difference values ​​of adjacent two samples and the sampling time interval.

10. The control method according to claim 7, characterized in that, In the frequency sweep operation mode, the speed of the drive motor (501) is controlled to change continuously to cover the frequency range between the preset low frequency and the preset high frequency.

Images