Bulk material conveying apparatus and method of use

Abstract

This invention belongs to the field of material conveying technology, specifically relating to a bulk material conveying device and its usage method. By collecting multi-point pressure response values ​​from key sections of the conveying pipeline, a spatial multi-point pressure difference correlation model is constructed. Based on the positive deviation of the first pressure difference, the negative deviation of the second pressure difference, the inverse correlation of dual change rates, and a constant feeding rate, the system accurately identifies the precursory state of blockage. After identification, a tiered unblocking process is implemented: the first stage maintains a constant main air source pressure and adaptively adjusts the pulse pressure, frequency, and feeding rate; if the first stage is ineffective or the pressure difference continues to worsen, the second stage is initiated, increasing the main air source pressure and pulse frequency. After unblocking, an asymmetric step sequence is used to gradually restore operating parameters, continuously monitoring the pressure difference change rate during the restoration process to avoid secondary blockage. This invention achieves accurate identification of precursory blockages, dynamic adaptation of tiered unblocking, and a stable and controllable restoration process, significantly improving the operational reliability of the pneumatic conveying system.

Description

Technical Field

[0001] This invention belongs to the field of material conveying technology, specifically relating to a bulk material conveying device and its usage method. Background Technology

[0002] Pneumatic conveying systems utilize compressed air as power to transport bulk materials in pipelines, and are widely used in industries such as chemical, building materials, and food processing. During pneumatic conveying, when material moisture fluctuates, particle size is uneven, or the feed rate is excessively high, localized blockages can easily occur at pipe bends, diameter changes, or long horizontal sections. To address this blockage problem, existing technologies primarily employ single-point pressure over-threshold detection combined with fixed-point air replenishment for unblocking.

[0003] However, the above methods have the following technical drawbacks: Regarding blockage identification, existing technologies use single-point pressure exceeding a threshold as the criterion. This implicitly assumes that blockage will inevitably lead to an increase in pressure at that monitoring point. However, in actual conveying processes, blockage formation is a gradual process. Before the blockage is fully formed, the pressure increase is not significant, making it difficult to trigger a threshold alarm. When the pressure reaches the alarm threshold, material has already accumulated severely, significantly increasing the difficulty of unblocking. Furthermore, single-point pressure monitoring cannot distinguish between localized blockages and overall system pressure fluctuations. When the air source pressure fluctuates or the feeding rate changes, false alarms are easily generated. Regarding unblocking strategies, existing technologies use a fixed-location, fixed-intensity air replenishment method, which cannot dynamically adjust the unblocking intensity according to the degree of blockage development. High-intensity air replenishment for minor blockages wastes energy, while fixed-intensity air replenishment for severe blockages is unlikely to create an effective impact, resulting in a low unblocking success rate. Manual knocking or pipe dismantling for cleaning leads to conveying interruptions. The lack of a recovery control mechanism means that existing technologies restore the feeding rate and air source pressure all at once after unblocking, ignoring the impact of parameter mutations on the material's movement state, which can easily trigger secondary blockages.

[0004] Therefore, existing technologies suffer from technical problems such as delayed blockage identification, limited unblocking strategies, and lack of recovery control, necessitating a bulk material conveying device and its usage method. Summary of the Invention

[0005] In view of the above-mentioned shortcomings in the prior art, the present invention provides a bulk material conveying device and a method of use to solve the problems in the background art.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method of using a bulk material conveying device includes the following steps: Step 1: Collect pressure response values ​​from pressure monitoring nodes at the front, middle, and rear ends of key sections of the conveying pipeline; obtain the feeding rate of the feeder and the pressure reference value of the main conveying air source; Step 2: Construct the pressure difference parameters between adjacent monitoring nodes, including the first pressure difference between the front end and the middle section, and the second pressure difference between the middle section and the rear end, and calculate the rate of change of the first pressure difference and the second pressure difference over time respectively; Step 3: Establish a state discrimination model based on spatial multi-point pressure difference correlation. When the first pressure difference has a positive deviation from the reference first pressure difference and the second pressure difference has a negative deviation from the reference second pressure difference, the rate of change of the first pressure difference with time is positive and the rate of change of the second pressure difference with time is negative, and the feeding rate remains constant, it is determined to be a state of impending blockage. Step 4: After determining that the state is in the early stage of blockage, the first level of unblocking is executed. When the unblocking conditions are met that the first pressure difference is not greater than the reference first pressure difference and its rate of change over time is not greater than zero, this step is terminated. During execution, if the rate of change of the first pressure difference over time is greater than the initial rate of change and this state continues for more than a number of sampling cycles, the second level of unblocking is executed. Step 5: If the first pressure difference is still higher than the benchmark first pressure difference after the first stage of unblocking has been performed for a preset time, then the second stage of unblocking is performed; when the first pressure difference is not greater than the benchmark first pressure difference and its rate of change over time is not greater than zero, this step is terminated; if the blockage is not cleared after the second stage of unblocking has been performed for a preset time, i.e. the first pressure difference is still higher than the benchmark first pressure difference, then the system issues an alarm and stops delivery. Step 6: Construct an asymmetric recovery mechanism. If the unblocking is completed by the first level of unblocking, the parameters are restored according to the step sequence; if the unblocking is completed by the second level of unblocking, the parameters are restored according to the step sequence. During the recovery process, when the rate of change of the first differential pressure over time is positive and lasts for at least three sampling cycles, the corresponding level of unblocking operation is re-executed.

[0007] Furthermore, the key sections in step 1 are the bends, diameter changes, or long straight sections of the conveying pipeline.

[0008] Furthermore, in step 1, the pulse air supply valve is installed upstream of the critical section, and the distance between the pulse air supply valve and the critical section is less than or equal to a set multiple of the pipe diameter. The pulse air supply valve is connected to the air storage tank through a pipeline, and a pressure regulating valve is installed on the pipeline. The set multiple ranges from 2 to 5 times the pipe diameter.

[0009] Furthermore, in step 4, the first stage of unblocking involves maintaining the main conveying air source pressure constant, adjusting the pulse pressure based on the main conveying air source pressure, injecting pulse airflow into the conveying pipeline, and adjusting the feeding rate; the second stage of unblocking involves increasing the main conveying air source pressure, injecting pulse airflow with the adjusted pulse frequency and duty cycle, and further adjusting the feeding rate.

[0010] Furthermore, the pulse frequency used in the first stage of unblocking is determined based on the pressure sampling period or the response time of the pulse air supply valve, and the pulse frequency used in the second stage of unblocking is determined based on the ratio of the first differential pressure change rate to the initial change rate, with the duty cycle decreasing as the pulse pressure increases.

[0011] Furthermore, the pulse pressure is determined by the degree to which the main delivery gas source pressure and the first pressure difference exceed the reference first pressure difference.

[0012] Furthermore, the adjustment of the feeding rate is to reduce the feeding rate, which is determined based on the ratio of the reference first pressure difference to the current first pressure difference; the further adjustment of the feeding rate is to further reduce the feeding rate, which is determined based on the feeding rate after the first stage of unblocking, the reference first pressure difference, and the current first pressure difference.

[0013] Furthermore, the first and second reference pressure differences in step 3 are the arithmetic averages calculated after the system continuously collects pressure data under stable delivery conditions, and the collection time is determined according to the pressure fluctuation cycle.

[0014] Furthermore, the initial change rate in step 4 is the rate of change of the first differential pressure over time when the condition is determined to be a precursor to blockage.

[0015] A bulk material conveying device includes a feeder, a conveying pipeline, an air source, and a control system connected in sequence. A pulse air supply valve is installed upstream of the critical section of the conveying pipeline. The air source is an air storage tank. The pulse air supply valve is connected to the air storage tank through a high-pressure air pipeline. A pressure regulating valve is installed on the pipeline between the pulse air supply valve and the air storage tank. The distance between the pulse air supply valve and the critical section is less than or equal to a preset multiple of the pipeline diameter. Pressure monitoring nodes are respectively installed at the front end, middle section and rear end of the critical section. The control system is electrically connected to the pressure monitoring nodes, the feeder, the air source and the pulse air supply valve.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention constructs a dual differential pressure and differential pressure change rate discrimination model by using three-point pressure monitoring at the front, middle and rear of the key section. The positive deviation of the first differential pressure, the negative deviation of the second differential pressure, and the reverse correlation of the dual change rates are used as the basis for judging the early signs of blockage. Compared with the traditional single-point pressure threshold detection, it can accurately identify the blockage trend in the early stage when the material is slightly accumulated and not completely blocked. It effectively avoids misjudgment and missed judgment caused by pressure fluctuation and changes in material supply, significantly improves the real-time performance and accuracy of blockage identification, reduces the probability of complete pipeline blockage from the source, reduces the frequency of downtime for cleaning and pipeline disassembly and assembly, and improves the continuous operation stability of the conveying system. 2. By setting up a tiered unblocking mechanism, the first stage of unblocking maintains a constant main air source pressure and adaptively adjusts the pulse pressure and feeding rate. The second stage of unblocking increases the main air source pressure, raises the pulse frequency, and matches the corresponding duty cycle. At the same time, it further reduces the feeding rate according to the pressure difference, so that the unblocking intensity and the degree of blockage development are dynamically adapted, solving the problems of low efficiency and high energy consumption of traditional fixed-intensity air supply unblocking. Combined with the control logic that adaptively adjusts the duty cycle with the pulse pressure, it avoids airflow overload and flow field turbulence while ensuring the unblocking impact force, significantly improving the unblocking success rate of light and moderate blockages and reducing equipment impact and pipeline wear. 3. By constructing an asymmetric stepped recovery mechanism, the material supply rate and air source pressure are restored using differentiated steps and intervals based on the level of blockage. During the recovery process, the differential pressure change rate is continuously monitored and real-time intervention is implemented to prevent secondary blockages caused by sudden parameter changes. Compared to the traditional one-time restoration method after blockage, this mechanism can smoothly rebuild a stable conveying flow field within the pipeline, improving the reliability of the system's recovery process. The overall solution achieves integrated control of precursor identification, graded blockage, and smooth recovery without altering the main conveying structure. It is easy to modify, highly versatile, and can significantly improve the operating efficiency and service life of pneumatic conveying systems for bulk materials. Attached Figure Description

[0017] Figure 1 This is a step diagram illustrating the method of using a bulk material conveying device according to the present invention; Figure 2 This is a simplified structural diagram of a bulk material conveying device according to the present invention; Figure 3 This is a schematic diagram of a bulk material conveying device according to the present invention; The reference numerals in the accompanying drawings include: 1. Feeder; 2. Critical section; 3. Conveying pipeline; 4. Pressure monitoring point; 5. Pulse air supply valve; 6. Air storage tank. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0019] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual images, and should not be construed as limiting the scope of this application. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0020] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present application. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0021] In the description of this invention, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating a connection between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication between two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] Example 1: like Figure 1-3 As shown, a method of using a bulk material conveying device includes the following steps: Step 1: Collect the pressure response values ​​of the pressure monitoring nodes at the front, middle and rear ends of the key sections of the conveying pipeline; simultaneously obtain the feeding rate of the feeder and the pressure reference value of the main conveying air source; the key sections are the bends, diameter changes or long straight sections of the conveying pipeline.

[0023] Specifically, collect front-end pressure response values. Mid-section pressure response value and backend pressure response value The feed rate of the feeder is The pressure reference value of the main gas supply is ; Step 2: Construct the pressure difference parameters between adjacent monitoring nodes, including the first pressure difference between the front end and the middle section, and the second pressure difference between the middle section and the rear end, and calculate the rate of change of the first pressure difference and the second pressure difference over time respectively; Specifically, during the conveying process, the first pressure difference is calculated as follows: The second pressure difference is The rate of change of the first pressure difference with time is The rate of change of the second pressure difference with time is ; Step 3: Establish a state discrimination model based on spatial multi-point pressure difference correlation. When the first pressure difference has a positive deviation from the reference first pressure difference and the second pressure difference has a negative deviation from the reference second pressure difference, the rate of change of the first pressure difference with time is positive and the rate of change of the second pressure difference with time is negative, and the feeding rate remains constant, it is determined to be a state of impending blockage. The control system establishes a state discrimination model based on spatial multi-point pressure difference correlation. A state is determined to be a precursor to blockage when the following conditions are simultaneously met: (1) ,and ; (2) ,and ; (3) Maintain constant; Furthermore, the initial rate of change Its value is the rate of change of the first differential pressure over time during the pre-blockage state, i.e. .

[0024] First differential pressure benchmark and the second differential pressure of the benchmark This is the arithmetic mean of the pressure data continuously collected by the system under stable delivery conditions. The collection time is determined based on the pressure fluctuation cycle.

[0025] The pressure fluctuation period is the time interval between two adjacent peaks of the pressure signal. The acquisition duration is 3-5 pressure fluctuation periods to ensure that the acquired data covers the complete pressure fluctuation pattern, so that the reference pressure difference can reflect the true steady-state operating conditions.

[0026] Specifically, before the system is put into operation, the reference differential pressure is calibrated first. The feeder and main air supply are started with normal conveying parameters to bring the system into a stable conveying state. A stable conveying state means that the fluctuation range of the first and second differential pressures continuously monitored does not exceed ±5% of their respective average values, and this state lasts for at least 5 seconds. The ±5% threshold is determined based on the measurement accuracy of the pressure sensor (usually ±0.5%) and the normal fluctuation range of the on-site operating conditions. This eliminates measurement noise and normal fluctuations, while preventing the system from failing to reach a stable state due to an overly strict threshold. After confirming that the system is in a stable conveying state, data acquisition is initiated. The acquisition duration is determined based on the pressure fluctuation cycle. The pressure fluctuation cycle refers to the time interval between two adjacent peaks of the pressure signal, which is determined by the feed pulsation of the feeder and the discontinuous flow of material in the pipeline. The acquisition duration is 3 to 5 pressure fluctuation cycles, with 3 cycles being the minimum requirement to meet statistical representativeness, and 5 cycles being suitable for applications with higher accuracy requirements, to ensure that the acquired data can cover the complete pressure fluctuation pattern.

[0027] Preferably, in this embodiment, the measured pressure fluctuation period is 2 seconds, and the sampling duration is 3 fluctuation periods, i.e., 6 seconds. A sampling frequency of 5Hz (sampling period) is used. The system continuously collects pressure response values ​​from three pressure monitoring nodes at the front, middle, and rear ends of the key section (within seconds). The sampling frequency is 5Hz, which is 2.5 times the highest frequency of the pressure signal (approximately 2Hz, corresponding to the shortest pressure fluctuation period of 0.5 seconds), satisfying the Nyquist sampling theorem and effectively capturing details of pressure changes. The typical scan cycle of an industrial PLC is 0.1 to 0.5 seconds; 0.2 seconds is a common choice in industrial control, with broad hardware support and a moderate computational burden.

[0028] Calculate the arithmetic mean of the first and second pressure differentials from the collected continuous pressure data. and These are the first and second reference differential pressures, which are stored in the storage unit of the control system.

[0029] Step 4: After determining that the state is in the early stage of blockage, the first stage of unblocking is executed. The main delivery air source pressure is kept constant, and the pulse pressure is adjusted based on the main delivery air source pressure to inject pulse airflow into the delivery pipeline and adjust the feeding rate. When the unblocking condition is met that the first pressure difference is not greater than the reference first pressure difference and its rate of change with time is not greater than zero; during the execution, if the rate of change of the first pressure difference with time is greater than the initial rate of change, and this state continues for more than a number of sampling cycles (more than 3 cycles), then the second stage of unblocking is executed. Furthermore, the pulse pressure is determined by the degree to which the main delivery gas source pressure exceeds the reference first pressure difference. Specifically, the main delivery gas source pressure is maintained. The constant pulse pressure is calculated using the following formula: in, The pressure of the first unblocking pulse, as measured in this embodiment, is... ,but = The pressure output from the gas storage tank is adjusted to this value through the pressure regulating valve.

[0030] Furthermore, the pulse frequency used for the first stage of unblocking is determined based on the pressure sampling cycle or the response time of the pulse air supply valve. Specifically, the pulse frequency used for the first stage of unblocking is... It should be noted that this value is based on the valve response time. The pulse frequency must be within seconds. To ensure the valve can fully open and close, the pulse frequency should meet the following requirements. The relationship. In this embodiment... ,therefore Yes, it is feasible. If the valve response time is longer, the pulse frequency should be reduced accordingly. Generally, the pulse frequency range is from 2Hz to 10Hz.

[0031] The duty cycle decreases as the pulse pressure increases. The mechanism is that with higher pulse pressure, the energy of a single impact is sufficient to disrupt material buildup. Reducing the duty cycle avoids continuous high-pressure airflow that can cause flow field turbulence, material splashing, and pipe overload, thus maintaining system stability while ensuring effective unblocking. Calculated using the following formula: in, Duty cycle, For pulse pressure, The initial duty cycle corresponds to the duty cycle when the pulse pressure equals the main conveying air source pressure. This value is obtained through on-site calibration during the system commissioning phase, based on the valve characteristics of the pulse replenishment valve used in this embodiment and the characteristics of the conveyed material. Initial duty cycle calibration method: During system commissioning, maintain the main air supply pressure, close the feeder (no material in the pipeline), and send pulses into the pipeline at different duty cycles (0.1, 0.2, 0.3, 0.4, 0.5). Measure the pressure rise at the downstream end of the pulse replenishment valve (the upstream end of the critical section). Select a pressure rise greater than a set threshold. (That is, 10% of the main supply air pressure, based on engineering experience, which effectively distinguishes the flow capacity of pulsed airflow without wasting energy due to excessively high duty cycles caused by an excessively low threshold.) The minimum duty cycle is used as the initial duty cycle. .

[0032] In this embodiment, the initial duty cycle obtained through calibration is 0.3, corresponding to the duty cycle when the pulse pressure equals the main delivery air source pressure. This value is calibrated during the commissioning phase based on valve characteristics and material characteristics. First unblocking pulse pressure. = Substituting into the above calculation formula, the duty cycle for the first stage of dredging is: in, The first level of dredging is the duty cycle.

[0033] Furthermore, adjusting the feeding rate to reduce the feeding rate is determined based on the ratio of the reference first pressure difference to the current first pressure difference; specifically, reducing the feeding rate is calculated using the following formula: in, To reduce the feeding rate, In this embodiment, the initial feeding rate is... .

[0034] During the first phase of dredging, the control system monitored in real time. The condition for jumping to the second level of unblocking is that if the rate of change of the first pressure difference over time is greater than the initial rate of change. If this indicates that the blockage is accelerating, then the second level of dredging should be implemented immediately.

[0035] The termination condition is determined when... and When the blockage is cleared, the first blockage is terminated, and the material supply rate is restored in a stepwise sequence.

[0036] Step 5: If the first pressure difference is still higher than the benchmark first pressure difference after the first stage of unblocking has been performed for a preset time, the second stage of unblocking is performed to increase the pressure of the main conveying air source and inject pulse airflow with the adjusted pulse frequency and duty cycle to further adjust the feeding rate; when the first pressure difference is not greater than the benchmark first pressure difference and its rate of change over time is not greater than zero, this step is terminated; if the blockage is not cleared after the second stage of unblocking has been performed for a preset time, i.e. the first pressure difference is still higher than the benchmark first pressure difference, the system issues an alarm and stops conveying.

[0037] Specifically, the preset duration refers to the waiting time allowed for the first level of unblocking to take effect, determined based on the pressure response time or material conveying speed. The pressure response time can be determined experimentally. After activating the pulse air supply valve for pulse air supply, the time interval from pulse activation to the pressure monitoring node detecting a pressure change is recorded. The preset duration is taken as 2 to 3 times this time interval. When determined based on the material conveying speed, the preset duration is taken as 1.5 to 3 times the time it takes for the material to be conveyed from the pulse air supply valve location to the end of the critical section. In this embodiment, the pressure response time is 5 seconds, therefore the preset duration is 10 seconds.

[0038] The control system can also dynamically adjust the preset duration based on historical dredging records. The control system has a dynamic adaptive adjustment function. The system records the actual successful time of each first-level dredging operation, the time interval from activation to the start of the first pressure differential decrease, and takes the average time of the three most recent successful dredging operations as the preset duration for the next operation. When the second-level dredging is triggered, the system analyzes whether the preset duration is too short, leading to premature escalation, and appropriately increases the preset duration if necessary.

[0039] Furthermore, if the first-level dredging process continues for the preset duration, at this point... Then, the second stage of unblocking is performed; the main conveying air source pressure is increased, and the pulse airflow is injected with the adjusted pulse frequency and duty cycle to further adjust the feeding rate; the increased main conveying air source pressure is calculated according to the following formula: The pulse pressure at this time is: in, To increase the pressure of the main gas supply, The second-level unblocking pulse pressure is as follows: The main supply air source pressure after the boost shall not exceed 0.8 times the rated safety pressure of the system, and the pulse pressure shall not exceed 0.7 times the rated pressure of the pipeline. (The above coefficients refer to the general requirement in the field of industrial pipeline safety design that the operating pressure shall not exceed 80% of the design pressure. At the same time, considering the instantaneous impact effect of the pulse pressure, a more conservative safety margin of 0.7 times is taken to avoid excessive pressure superposition causing equipment damage or safety risks.)

[0040] Furthermore, the pulse frequency used in the second-stage unblocking is determined based on the ratio of the first pressure difference change rate to the initial change rate, and the duty cycle decreases as the pulse pressure increases. Preferably, the pulse frequency used in the second-stage unblocking is determined based on the ratio of the first pressure difference change rate to the initial change rate, i.e.: in, For the pulse frequency used in the second-stage unblocking process, the upper limit of the pulse frequency is set at 20Hz, which is the highest reliable operating frequency for commonly used valves in the industry. The rationale is that when the frequency exceeds 20Hz, the valve response time is insufficient to complete the full opening-closing action, leading to the failure of pulse airflow superposition and the actual output approaching continuous airflow rather than an effective pulse. Simultaneously, excessively high switching frequencies will cause increased fluctuations in the gas supply pressure of the storage tank, preventing the pulse impact energy from being fully established and thus weakening the unblocking effect. Limiting the frequency to within 20Hz ensures reliable response of the pulse replenishment valve, ensuring that each pulse impact has sufficient unblocking energy to maintain stable gas supply pressure in the storage tank.

[0041] The rule for determining the duty cycle of the second-level dredging is exactly the same as that of the first-level dredging, and the specific calculation is as follows: in, In this embodiment, the duty cycle for the second-stage dredging is... Substitute into the calculation formula, that is 2.

[0042] Furthermore, the feeding rate is further adjusted to a further reduced feeding rate, determined based on the feeding rate after the first stage of unblocking, the baseline first pressure difference, and the current first pressure difference. The further reduced feeding rate is calculated using the following formula: in, To further reduce the feeding rate.

[0043] The termination condition is: and At that time, the second-level dredging is terminated, and the feeding rate and main conveying air source pressure are restored in a step sequence.

[0044] Step 6: Construct an asymmetric recovery mechanism. If the dredging is completed by the first stage, the material supply rate will be gradually restored to the normal value in a step sequence. If the dredging is completed by the second stage, the feeding rate and the main conveying air source pressure will be gradually restored to normal values ​​in a step sequence. During the recovery process, the control system continuously monitors the system. When the rate of change of the first differential pressure over time is positive and lasts for at least three sampling cycles, the corresponding level of unblocking operation is re-executed.

[0045] Specifically, the number of steps and intervals in the ladder sequence are dynamically adjusted by the control system based on actual conditions, without the need for preset fixed values. The adjustment principles are as follows: The number of steps is determined based on the degree to which the current differential pressure deviates from the baseline differential pressure. The greater the deviation, the more steps are required (the smoother the recovery); the smaller the deviation, the fewer steps are required (the faster the recovery).

[0046] The interval time is determined based on the pipeline length and material characteristics. The longer the pipeline and the worse the material flow, the longer the interval time.

[0047] In a preferred implementation, the number of steps determines the smoothness of the recovery. Too few steps (e.g., less than 3 steps) will lead to too rapid recovery, and sudden changes in the feeding rate or pressure may trigger blockage again; too many steps (e.g., more than 15 steps) will lead to excessively long recovery time, affecting conveying efficiency. 3 to 7 steps (Level 1) and 5 to 15 steps (Level 2) represent a balance between preventing secondary blockage and production efficiency. Level 2 recovery has more steps than Level 1 because the system stability is worse after Level 2 unblocking, requiring a smoother recovery. The interval time needs to be greater than the system's pressure response time (typically 0.5 to 1 second) to ensure that the system reaches a new steady state after each recovery step. At the same time, the interval time should not be too long to avoid affecting production efficiency. 1 to 3 seconds (Level 1) and 2 to 8 seconds (Level 2) represent a balance between system stability and recovery efficiency. Level 2 recovery interval time is longer than Level 1 because a longer stabilization observation time is required after Level 2 unblocking.

[0048] The number of steps for step recovery is determined based on the degree of deviation of the first differential pressure from the reference differential pressure: ≤20%, 3-5 steps; 20%-50%, 6-10 steps; >50%, 10-15 steps. The interval between each step is 1-3 seconds; the longer the pipeline and the worse the material flowability, the longer the interval. In this embodiment, the first-stage unblocking takes 5 steps with a 2-second interval between each step; the second-stage unblocking takes 10 steps with a 5-second interval between each step. These values ​​are in the middle range of their respective ranges and can adapt to most working conditions.

[0049] A bulk material conveying device includes a feeder, a conveying pipeline, an air source, and a control system connected in sequence. A pulse air supply valve is installed on the upstream side of the critical section of the conveying pipeline. The air source is an air storage tank. The pulse air supply valve is connected to the air storage tank through a high-pressure air pipeline. A pressure regulating valve is installed on the pipeline between the pulse air supply valve and the air storage tank. The distance between the pulse air supply valve and the critical section is less than or equal to a preset multiple of the pipeline diameter. Pressure monitoring nodes are set at the front, middle and rear ends of the critical section. The control system is electrically connected to the pressure monitoring nodes, the feeder, the air source and the pulse air supply valve.

[0050] Furthermore, the pulse air supply valve is installed upstream of the critical section, and the distance from the critical section is less than or equal to a set multiple of the pipe diameter. The pulse air supply valve is connected to the air storage tank via a pipeline, which is equipped with a pressure regulating valve. The pulse air supply valve should be a fast-response solenoid valve or a pilot-operated pneumatic valve, with a response time of [missing information]. It should not be greater than In this embodiment... Taking 5Hz as an example, the requirements are... Seconds. If the response time of the on-site valves cannot meet the requirements, the system should automatically adjust the pulse frequency to [value missing]. .

[0051] Specifically, the multiplier is set based on the following: when the pulsed airflow propagates in the pipe, its pressure decreases exponentially with the propagation distance. If the distance is too short (e.g., less than 1 times the pipe diameter), the pulsed airflow concentrates on impacting a localized area and cannot cover the entire critical section; if the distance is too long (e.g., greater than 5 times the pipe diameter), the pulse energy attenuates too much, losing its unblocking effect. Engineering experience shows that 2 to 5 times the pipe diameter is the effective operating distance.

[0052] In this embodiment, the multiplier is set to 3 times the pipe diameter. This value is based on the fact that when the pulsed airflow propagates in the pipe, its pressure decreases exponentially with the propagation distance. If the distance is too short (e.g., less than 1 times the diameter), the pulsed airflow concentrates its impact on a localized area, failing to cover the entire critical section; if the distance is too long (e.g., greater than 5 times the diameter), the pulse energy attenuates too much, losing its unblocking effect. Engineering experience shows that 2 to 5 times the pipe diameter is the effective operating distance. Within the range of 3 times the diameter, the pulse pressure attenuates by approximately 20%-30%, still maintaining effective impact force.

[0053] The above are merely embodiments of the present invention. The circuits, electronic components, and modules involved are all prior art, fully achievable by those skilled in the art, and require no further explanation. The content protected by this application does not involve improvements to the software and methods. Commonly known structures and characteristics in the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are able to access all prior art in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A method of using a bulk material conveying device, characterized in that: Includes the following steps: Step 1: Collect pressure response values ​​from pressure monitoring nodes at the front, middle, and rear ends of key sections of the conveying pipeline; obtain the feeding rate of the feeder and the pressure reference value of the main conveying air source; Step 2: Construct the pressure difference parameters between adjacent monitoring nodes, including the first pressure difference between the front end and the middle section, and the second pressure difference between the middle section and the rear end, and calculate the rate of change of the first pressure difference and the second pressure difference over time respectively; Step 3: Establish a state discrimination model based on spatial multi-point pressure difference correlation. When the first pressure difference has a positive deviation from the reference first pressure difference and the second pressure difference has a negative deviation from the reference second pressure difference, the rate of change of the first pressure difference with time is positive and the rate of change of the second pressure difference with time is negative, and the feeding rate remains constant, it is determined to be a state of impending blockage. Step 4: After determining that the state is in the early stage of blockage, the first level of unblocking is executed. When the unblocking conditions are met that the first pressure difference is not greater than the baseline first pressure difference and its rate of change over time is not greater than zero, this step is terminated. During execution, if the rate of change of the first pressure difference over time is greater than the initial rate of change, the second level of unblocking is executed. Step 5: If the first pressure difference is still higher than the benchmark first pressure difference after the first-level dredging has been performed for a preset time, the second-level dredging will be performed. This step will be terminated after the dredging is completed. If the blockage is not cleared after the second-level dredging has been performed for a preset time, the system will issue an alarm and stop the delivery. Step 6: Construct an asymmetric recovery mechanism. If the unblocking is completed by the first level, the feeding rate is gradually restored in a step sequence. If the unblocking is completed by the second level, the feeding rate and the main conveying gas source pressure are gradually restored in a step sequence. During the recovery process, when the rate of change of the first differential pressure over time is positive and lasts for no less than three sampling cycles, the unblocking operation of the corresponding level is re-executed.

2. The method of using a bulk material conveying device as described in claim 1, characterized in that: The key sections in step 1 are the bends, diameter changes, or long straight sections of the pipeline.

3. The method of using the bulk material conveying device as described in claim 1, characterized in that: In step 1, a pulse air supply valve is installed upstream of the critical section. The distance between the pulse air supply valve and the critical section is less than or equal to a set multiple of the pipe diameter. The pulse air supply valve is connected to the air storage tank through a pipeline, and a pressure regulating valve is installed on the pipeline.

4. The method of using a bulk material conveying device as described in claim 1, characterized in that: The first stage of unblocking in step 4 is to keep the main conveying air source pressure constant, adjust the pulse pressure based on the main conveying air source pressure, inject pulse airflow into the conveying pipeline, and adjust the feeding rate. The second stage of unblocking involves increasing the pressure of the main conveying air source and injecting pulsed airflow with adjusted pulse frequency and duty cycle to further regulate the feeding rate.

5. The method of using a bulk material conveying device as described in claim 4, characterized in that: The pulse frequency used in the first stage of unblocking is determined based on the pressure sampling period or the response time of the pulse air supply valve. The pulse frequency used in the second stage of unblocking is determined based on the ratio of the first differential pressure change rate to the initial change rate. The duty cycle decreases as the pulse pressure increases.

6. The method of using a bulk material conveying device as described in claim 4, characterized in that: The pulse pressure is determined by the degree to which the main delivery gas source pressure and the first pressure difference exceed the reference first pressure difference.

7. The method of using a bulk material conveying device as described in claim 4, characterized in that: The adjustment of the feeding rate is to reduce the feeding rate, and the reduced feeding rate is determined based on the ratio of the reference first pressure difference to the current first pressure difference; the further adjustment of the feeding rate is to further reduce the feeding rate, and the further reduced feeding rate is determined based on the feeding rate after the first stage of unblocking, the reference first pressure difference, and the current first pressure difference.

8. The method of using a bulk material conveying device as described in claim 1, characterized in that: The first and second reference pressure differences in step 3 are the arithmetic averages calculated after the system continuously collects pressure data under stable delivery conditions. The collection time is determined according to the pressure fluctuation cycle.

9. The method of using a bulk material conveying device as described in claim 1, characterized in that: The initial change rate in step 4 is the rate of change of the first differential pressure over time when the condition is determined to be a precursor to blockage.

10. A bulk material conveying device, applicable to the method of using the bulk material conveying device according to any one of claims 1-9, characterized in that: Includes a feeder, conveying pipeline, air source, and control system connected in sequence. The gas source is a gas storage tank. A pulse gas supply valve is installed on the upstream side of the critical section of the delivery pipeline. The pulse gas supply valve is connected to the gas storage tank through a high-pressure gas pipeline. A pressure regulating valve is installed on the pipeline between the pulse gas supply valve and the gas storage tank. The distance between the pulse gas supply valve and the critical section is less than or equal to a preset multiple of the pipeline diameter. Pressure monitoring nodes are respectively installed at the front end, middle section and rear end of the critical section. The control system is electrically connected to the pressure monitoring nodes, the feeder, the gas source and the pulse gas supply valve.

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