Transportation method for low-residue and high-efficiency unloading of dry-mixed mortar

Abstract

The invention relates to the technical field of bulk material transportation, and discloses a dry-mixed mortar low-residue efficient unloading transportation method which is based on a discretization pneumatic unit array with the surface covered with a pneumatic elastic variable stiffness one-way valve, and switching of a valve body between a vertical fluidization mode and a horizontal conveying mode is achieved by controlling input pressure. The method comprises the following steps: firstly, synchronously applying fluidization maintaining pressure to a whole domain, so that a material is in a subcritical quasi-fluid state without static friction, and particle segregation is prevented; then a time sequence traveling wave signal is generated, a control unit sequentially outputs traveling wave driving pressure, and directional horizontal jet flow is generated to drive the materials to move towards a discharging opening; and in the later discharging stage, high-frequency pulse excitation is applied to the locked edge area, the central negative pressure induction module is cooperatively started to construct a push-pull flow field, and residual materials are forcibly gathered and discharged. The problems of segregation, mousehole residues and dead corner residues in the dry-mixed mortar transportation process are effectively solved, and the unloading efficiency is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the bulk material transportation field, in particular to a low-residual efficient unloading transportation method for dry-mixed mortar. BACKGROUND

[0002] At present, the bulk transportation of dry-mixed mortar mainly relies on tank special vehicles equipped with pneumatic unloading systems. Such vehicles usually have a fluidized bed structure at the bottom of the tank. The working principle is to fill compressed air into the bottom of the material layer through a gas-permeable fabric or a porous plate to reduce the internal friction between the powder particles, so that the material presents a quasi-fluid state, and then flows to the discharge port under the action of the pressure difference in the tank.

[0003] However, dry-mixed mortar is a composite material composed of aggregates, cementitious materials and various additives. There are significant differences in particle size and density between the components. In order to ensure the flowability of coarse aggregates, the traditional fluidized bed unloading technology often needs to maintain a high air flow rate. This high-intensity continuous air flow can easily cause violent boiling fluidization inside the material layer, causing particles with higher density or larger particle size to sink, while light micro-powder to float, thereby causing segregation of the material. This segregation phenomenon during transportation can directly damage the pre-set uniformity of the mortar ratio, affecting the final construction quality.

[0004] In addition, due to the relatively fixed air flow distribution of the traditional fluidized bed, the air flow tends to find the path with the smallest resistance to penetrate the material layer. During the unloading process, once the air flow breaks through the vertical channel in the local material layer, the compressed gas will be short-circuited and discharged from the channel, unable to continue to push the material around the channel, resulting in channeling or mouse hole phenomenon in the tank, causing a large amount of material to be retained inside the tank body and unable to be discharged. For the material distributed at the edge of the tank body bottom, around the reinforcing rib and in the corner area, due to being far away from the central fluidization area and lacking active horizontal thrust, it often forms a dead corner that is difficult to clean. The conventional treatment method is to rely on a hydraulic mechanism to lift the tank body by a large margin and use gravity to assist sliding. This not only is cumbersome to operate, but also increases the safety risk of vehicle rollover at the work site. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a low-residual efficient unloading transportation method for dry-mixed mortar, which solves the problems of segregation and stratification of dry-mixed mortar components caused by density difference due to excessive fluidization in the traditional pneumatic unloading process, the problems of mouse hole and channeling caused by air flow short circuit leading to unloading interruption, and the problem of residual material in the dead corner at the bottom edge of the tank body being difficult to completely clean without lifting the tank body.

[0006] To achieve the above purpose, the present application is implemented by the following technical solutions: A low-residual efficient unloading transportation method for dry-mixed mortar, comprising the following steps: S1, system initialization, set fluidization maintaining pressure and traveling wave driving pressure according to material properties; S2, global subcritical pre-fluidization, apply the fluidization maintaining pressure to the array of discrete pneumatic units globally to make the material in a quasi-fluid state to eliminate static friction; S3, time-sequenced traveling wave directional conveying, generate time-sequenced traveling wave control signals to control the units in the array of discrete pneumatic units to apply the traveling wave driving pressure in sequence, generate directional horizontal jet flow by modal switching of the pneumatic elastic variable stiffness valve to drive the material to move towards the discharge port; S4, boundary residual convergence cleaning, when the monitored discharge flow is lower than the preset threshold, lock the discrete pneumatic units located at the edge area of the transport tank, apply a pulse modulated pressure signal, and start the negative pressure induction module to build a pressure gradient field pointing from the edge to the center, and then discharge the residual material to the center area.

[0007] The pneumatic elastic variable stiffness valve has a critical deformation threshold pressure; In the S2, the fluidization maintaining pressure is less than the critical deformation threshold pressure, and the pneumatic elastic variable stiffness valve is in a vertical fluidization mode, and the airflow penetrates vertically upward; In the S3, the traveling wave driving pressure is greater than or equal to the critical deformation threshold pressure, the pneumatic elastic variable stiffness valve is switched to a horizontal conveying mode by structural deformation, and the airflow is deflected to form a horizontal jet flow in the discharge direction.

[0008] In the S2, the global subcritical pre-fluidization specifically includes: The global airflow velocity is controlled to generate vertical aerodynamic lift that only balances part of the effective gravity of the material layer, reduces the internal friction angle between the material particles, and limits the airflow velocity to prevent boiling fluidization that causes macroscopic mixing of the material.

[0009] In the S3, the time-sequenced traveling wave directional conveying specifically includes: The array of discrete pneumatic units is logically grouped by rows, and the high-pressure excitation window is controlled to move from the direction away from the discharge port to the direction close to the discharge port according to a preset traveling wave excitation function; The pneumatic units at the peak position are switched to the horizontal conveying mode to push the material, and the pneumatic units at the valley position are kept in the vertical fluidization mode to fill the gap.

[0010] In the S4, the discrete pneumatic units located at the edge area of the transport tank specifically refer to: Call the pre-stored position coordinate mapping data to select a set of pneumatic units located at the edge of the transport tank bottom plate and the dead angle area; The directional cut opening direction of the pneumatic elastic variable stiffness one-way valve in the pneumatic unit set is towards the longitudinal center axis of the transport tank body.

[0011] In the S4, the applied pulse modulation pressure signal specifically includes: The pressure signal superimposed with a high-frequency pulsation component is output to the discretized pneumatic unit of the locked edge area, driving the pneumatic elastic variable stiffness one-way valve to reciprocate near the opening and closing critical state, and generating mechanical vibration wave to strip the attached material.

[0012] In the S4, the synergistic negative pressure induction module specifically includes: A local low-pressure area is established above the center area of the transport tank body through the inner circulation balance pipe connected to the suction end of the compressor, and the positive pressure gas flow injected by the edge area pneumatic unit forms a push-pull synergistic convection closed loop in space, inhibiting dust diffusion and inducing material to converge to the center.

[0013] The boundary residual convergence cleaning further includes a cycle execution logic: When the edge material converges to the center area under the action of the push-pull flow field, the pulse modulation pressure signal and the negative pressure induction module are suspended, and the traveling wave conveying program of the center area pneumatic unit is activated to discharge the converged material until the residual amount meets the requirements.

[0014] The traveling wave excitation function adopts a Gaussian distribution function or a trapezoidal distribution function, and by adjusting the traveling wave advancing speed and the wave peak width parameters, the area and moving rate of the pneumatic unit in the horizontal conveying mode are controlled.

[0015] The elastic cover plate surface of the pneumatic elastic variable stiffness one-way valve is pre-fabricated with a directional cut, which produces nonlinear large deformation opening when the pressure exceeds the material elastic impedance, and automatically closes and locks when the pressure disappears.

[0016] The present application provides a dry-mixed mortar low-residual efficient unloading transportation method. It has the following beneficial effects: 1、The present application realizes the decoupling of fluidization drag reduction and directional conveying by controlling the modal switching of the pneumatic elastic variable stiffness one-way valve under different pressures, limits the gas flow to a non-boiling state in the full-domain subcritical pre-fluidization stage, effectively eliminates the segregation and stratification phenomenon of dry-mixed mortar caused by particle size difference, and realizes the horizontal directional conveying of the material without tilting the tank body by using high-pressure horizontal jet to directly transfer momentum in the traveling wave conveying stage, ensuring the grading stability of the finished mortar.

[0017] 2. This invention utilizes the time-sequential traveling wave control of a discrete pneumatic unit array to construct a dynamically shifting pressure gradient field. The periodic scanning of the high-pressure peak region forcibly alters the penetration path of the airflow in the material layer, thereby physically disrupting the formation conditions of fixed gas escape channels. This effectively suppresses the rat hole or channeling phenomena commonly seen in traditional pneumatic unloading processes, and enables the active and continuous propulsion of high-viscosity, easily caking materials.

[0018] 3. This invention adopts a clearance strategy that combines boundary pulse excitation and negative pressure induction, which solves the problem of material retention at the edges and dead corners of the transport tank. The high-frequency mechanical vibration of the edge pneumatic unit peels off the material attached to the wall, and the negative pressure push-pull flow field established by the internal circulation balance pipe forces the residual material at the edge to converge towards the center. This not only significantly reduces the unloading residue rate, but also greatly reduces the disorderly diffusion of dust inside the tank through the closed loop of the internal airflow. Attached Figure Description

[0019] Figure 1 This is a flowchart of the method of the present invention; Figure 2 This is a schematic diagram of the structure and mode switching principle of the pneumatic elastic variable stiffness check valve of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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 are within the scope of protection of the present invention. Example

[0021] Please see the appendix Figure 1 -Appendix Figure 2 This invention provides a method for transporting dry-mixed mortar with low residue and high efficiency, comprising the following steps: S100: Obtain the geometric parameters and material characteristic parameters of the transport tank, and set the fluidization maintenance pressure and traveling wave drive pressure of the pneumatic elastic variable stiffness check valve. S200 controls the multi-stage loop air supply network to apply fluidization maintenance pressure to the discrete pneumatic unit array, so that the pneumatic elastic variable stiffness check valve remains in a vertical flow guiding state, and performs full-domain subcritical pre-fluidization of the material in the tank. S300 generates traveling wave control signals that propagate along the unloading direction according to a preset timing sequence, and sequentially controls each row unit in the discrete pneumatic unit array to output traveling wave driving pressure, driving the pneumatic elastic variable stiffness check valve to switch to the horizontal guiding state for time-sequential traveling wave directional conveying. S400 monitors the unloading flow rate and locks the discrete pneumatic unit in the edge area when the flow rate is lower than the preset threshold. It outputs high-frequency pulse modulation pressure and starts the negative pressure induction module to perform boundary convergence and cleaning of residual materials.

[0022] The fluidization sustaining pressure and traveling wave driving pressure set in step S100 are based on the pressure response characteristics of a pneumatic elastic variable stiffness check valve. This valve body is located at the top airflow outlet of the discrete pneumatic unit and is used to convert the input scalar air pressure signal into a vector airflow signal with a specific direction.

[0023] The pneumatic flexible variable stiffness check valve includes a flexible cover plate covering the surface of the air outlet port of the pneumatic unit. This cover plate is made of a high-molecular polymer material with anisotropic elastic modulus characteristics. The surface of the cover plate has a pre-formed array of directional cuts. The geometry of these directional cuts can be fish-scale, arc-shaped, or V-shaped, and their openings face the same direction as the unloading direction of the transport tank. The operating state of the pneumatic flexible variable stiffness check valve depends on the input pressure. With critical deformation threshold pressure The numerical relationship between them, the critical deformation threshold pressure The critical point at which the valve body undergoes large structural deformation is determined by the material stiffness and thickness of the elastic cover plate and the geometric dimensions of the directional cut.

[0024] The specific response mechanism and flow field mode switching process of the pneumatic elastic variable stiffness check valve can be broken down into the following control logic steps: Vertical fluidized mode response: When the input pressure is applied by a multi-channel timing controller It is in the fluidization maintenance region, that is... When the aerodynamic pressure on the elastic cover plate is less than the elastic restoring force of the material, the directional cut opens only slightly, forming a microporous channel. The airflow path is constrained by the elastic walls on both sides of the cut and mainly escapes in a direction perpendicular to the normal of the bottom of the tank. In this mode, the airflow velocity vector is vertically upward, and its main function is to penetrate into the gaps between material particles, balance the gravity of the material, reduce the internal friction angle between particles, and keep the dry-mixed mortar in a loose quasi-fluid state, but without producing obvious horizontal displacement.

[0025] Horizontal conveying mode switching: When the input pressure applied by the multi-channel timing controller It leaps into the traveling wave driven region, that is... At this time, the aerodynamic pressure acting on the inner surface of the elastic cover plate overcomes the elastic resistance of the material, and the directional cut opens by nonlinear large deformation along the preset trajectory. The upper lip of the cut flips up and extends forward, changing the geometry of the airflow guiding channel. The airflow streamlines are deflected when passing through the deformed cut, forming a small angle with the bottom plane of the tank. In this mode, the horizontal jet not only provides levitation force, but more importantly, it generates a horizontal momentum component along the discharge direction, which directly does work on the material particles and propels the material layer forward.

[0026] Nonlinear modulation of vector angle: airflow ejection angle Defined as the angle between the airflow vector and the horizontal plane and the input pressure. There is a nonlinear mapping relationship between them. When the input pressure exceeds the critical deformation threshold pressure, the deformation of the elastic cover plate increases with the increase of the pressure difference, resulting in an increase in the injection angle. The flow gradually decreases and tends to be horizontal. Specifically, this physical process is characterized by the fact that the greater the input pressure, the greater the valve opening and the gentler the flow direction, and the higher the proportion of the horizontal delivery force. This pressure-angle coupling mechanism enables the system to achieve a seamless switch from vertical loosening to horizontal pushing of the flow field simply by adjusting the amplitude of the air supply pressure, without the need for mechanical transmission components.

[0027] Furthermore, to prevent backflow due to negative pressure or material backfilling and blockage, the directional cut of the pneumatic elastic variable stiffness check valve is designed with a self-locking structure. When the input pressure disappears... At that time, relying on the elastic rebound force of the material, the directional cut automatically closes and seals, blocking the material from entering the air passage system. The specific material selection and processing technology for the elastic cover plate, such as using wear-resistant elastomers like polyurethane or EPDM rubber, falls within the scope of what those skilled in the art can achieve using existing materials science, and will not be elaborated upon here. Through the above mechanism, this invention achieves the decoupling and temporal reconfiguration of fluidization and conveying functions on a single pneumatic structure.

[0028] After completing system initialization and parameter loading, the system enters the global subcritical pre-fluidization control stage. This stage aims to establish the basic rheological environment for gas-solid two-phase flow, and the specific implementation process includes the following logical steps: Calculation and setting of fluidization maintenance pressure: The multi-channel timing controller determines the fluidization maintenance pressure based on the input material characteristic parameters. To ensure that the pneumatically elastic variable stiffness check valve does not undergo large structural deformation that changes the flow direction during this stage, a fluidization maintenance pressure is set. The pressure must be strictly less than the critical deformation threshold pressure of the pneumatic elastic variable stiffness check valve. As a specific embodiment, fluidization maintenance pressure The critical deformation threshold pressure can be set. Within the range of 60% to 90%, the selection criterion for this pressure value is that the generated vertical airflow is sufficient to balance part of the gravity component of the material layer above, thereby reducing the effective stress and thus reducing the contact stress and internal friction angle between particles, but the airflow velocity has not yet reached the level of blowing the material up and suspending it and generating strong boiling and mixing.

[0029] Synchronous air supply across the entire array: The multi-channel timing controller sends a synchronous start command to the multi-stage loop air supply network. At this time, all pneumatic units in the discrete pneumatic unit array simultaneously receive a fluidization sustaining pressure. With the input of air source, under this pressure, the pneumatic elastic variable stiffness check valves covering the surface of all pneumatic units remain in the vertical fluidization mode. The airflow penetrates vertically upward into the material layer through the slightly opened slits, forming a uniform air cushion layer at the bottom of the transport tank. This process eliminates the static friction between the material and the bottom plate of the tank and destroys the stress arch structure formed during the material accumulation process, preventing material bridging or blockage that may occur during subsequent unloading.

[0030] Fluidization maintenance and energy optimization: Throughout the pre-fluidization phase, the controller maintains the fluidization maintenance pressure. Compared to traditional high-pressure full fluidization technology, the subcritical fluidization strategy adopted in this embodiment limits the total airflow flux, which not only reduces the energy consumption of compressed air, but more importantly, avoids the problem of coarse and fine particle segregation caused by excessive fluidization. Since the airflow velocity is limited to the level that can only overcome static friction, the material particles maintain a relatively static layered structure and do not undergo violent up-and-down tumbling and mixing, thereby ensuring the gradation uniformity of the dry-mixed mortar product. At the same time, this uniform background pressure field provides a homogeneous medium environment for the subsequent high-pressure traveling wave conveying, ensuring that the traveling wave driving force can be effectively transmitted to the depth of the material, rather than leaking in the low-resistance area.

[0031] For obtaining specific material characteristic parameters, the multi-channel timing controller can retrieve them from a preset database or estimate them in real time using back pressure signals fed back from pressure sensors connected to the transport tank. For example, by detecting the pressure rise rate at the initial gas supply, the bulk density and permeability of the material can be inferred, and the fluidization maintenance pressure can be dynamically adjusted. The specific values ​​are not detailed here, as this feedback-based parameter correction technique is a conventional closed-loop control method in this field.

[0032] After completing the subcritical pre-fluidization across the entire system, the system enters the main unloading stage. The core of this stage lies in constructing a pressure gradient field propagating longitudinally (from away from the discharge port to closer to the discharge port) on the discrete pneumatic unit array using a multi-channel timing controller. By utilizing the modal switching characteristics of the pneumatic elastic variable stiffness check valve, the active pushing of the material is achieved. This process specifically includes the following implementation steps: Generation of traveling wave pressure control signal: The multi-channel timing controller calculates the target pressure value of each pneumatic unit at each moment according to the preset traveling wave generation algorithm. In order to simulate the effect of a continuously advancing traveling wave on a discrete spatial array, the controller logically groups the pneumatic units at the bottom of the transport tank by row and sets the traveling wave excitation function, which describes the pressure amplitude with time. and spatial row index The changing pattern, in specific control logic, any first... The pneumatic unit at time Control pressure Pressure maintained by fluidization It is superimposed with the traveling wave excitation component, which adopts a spatially localized distribution function, such as a Gaussian distribution function or a trapezoidal distribution function, to ensure that only some regions are under high-pressure excitation at any given time, while the remaining regions remain in a fluidized state.

[0033] Gas-solid coupled directional conveying: In the region covered by the traveling wave crest, the horizontal jet airflow directly transfers momentum to the suspended material particles, generating a significant horizontal conveying flux. According to the gas-solid two-phase flow dynamics model, the material conveying flux is mainly dominated by the vector convection term. Specifically, the horizontal jet not only propels the material forward but also utilizes the high-speed shearing effect of the airflow to disrupt any potential agglomeration structures within the material. As the wave crest region continuously advances, the material in front is pushed towards the discharge port, while the material behind fills the gaps left after the wave crest departs under gravity and fluidization, forming a continuous material replenishment and conveying cycle.

[0034] Cyclic propulsion and channeling suppression: The controller periodically updates the time variable. The traveling wave crest is driven to cyclically scan from the beginning to the end of the array. This dynamically changing air supply area forcibly alters the airflow's penetration path within the material layer, preventing the gas from forming a fixed, low-resistance escape channel. This fundamentally suppresses mouse-hole or channeling phenomena, thus affecting the traveling wave's propulsion speed. and peak width parameter The controller can adaptively adjust based on the real-time monitored unloading flow rate. When the flow rate decreases, it can appropriately reduce the propulsion speed or increase the crest width to improve the conveying work done in a single scan.

[0035] In a specific embodiment, the pressure control logic described above can be described by a mathematical model as follows: ; In the formula, Representing the The longitudinal position coordinates of the aerodynamic unit. The term indicates speed. The moving Gaussian waveform envelope, as expressed by this formula, means that the control pressure, based on the background pressure, reaches its maximum driving value at the center of the peak and then decays towards both sides. This is achieved by adjusting parameters. and It can precisely control the propulsion rhythm and range of the traveling wave, and achieve efficient delivery of dry-mixed mortar with different viscosities and packing characteristics. The code implementation of the above algorithm in the controller, such as PID regulation or PLC ladder diagram programming, is a conventional technical means in the field of industrial automation control, and will not be elaborated here.

[0036] As the unloading process progresses into its later stages, the main material inside the tank has been discharged, leaving residual material primarily distributed in low-velocity areas such as the sidewall edges, around reinforcing ribs, and corners of the transport tank. To address this residual issue, the system executes a boundary convergence and cleaning step for the residual material. By altering the flow field boundary conditions and airflow excitation mode, a push-pull gas-solid transport environment is constructed. This process specifically includes the following implementation steps: Edge region locking and topology mapping: The multi-channel timing controller monitors the mass flow rate or photoelectric concentration signal at the unloading port in real time. When the monitored value is lower than the preset cleaning threshold, the controller automatically suspends the main unloading traveling wave program, calls the pre-stored tank geometry topology mapping table, and locks the discrete pneumatic unit set located at the edge and dead corner area of ​​the transport tank bottom plate. During physical installation, the pneumatic units within this assembly have pneumatic elastic variable stiffness check valves on their surfaces assembled at a specific angle. This ensures that the jet direction in the horizontal conveying mode is not directed towards the discharge port, but rather towards the longitudinal central axis area of ​​the transport tank, forming a centripetal converging flow guide layout.

[0037] High-frequency pulse modulation and aeroelastic flutter excitation: for locked edge aerodynamic unit assemblies The multi-channel timing controller no longer outputs a constant DC pressure signal, but instead outputs a pulse-modulated pressure signal superimposed with a high-frequency AC component. The signal drives the pneumatic elastic variable stiffness check valve to reciprocate rapidly near the critical state of opening and closing, inducing the valve body to generate pneumatic elastic flutter. This flutter effect has two physical effects: first, it generates high-frequency mechanical vibration waves that are transmitted to the local material layer, destroying the van der Waals forces and electrostatic adsorption forces between the fine powder particles and the tank wall; second, it generates pulsating high-speed airflow shear force, which peels off the material adhering to the wall layer.

[0038] The mathematical expression for this pulse-modulated pressure signal is: ; In the formula, It serves as the base bias pressure, used to maintain the valve body in a slightly open state; The pulse amplitude is set to ensure that the pressure peak can instantly exceed the critical deformation threshold pressure. The modulation frequency is set to be close to the natural frequency of the aeroelastic variable stiffness check valve material to induce a resonance effect and maximize the mechanical stripping energy.

[0039] Negative pressure induction and push-pull synergistic flow field construction: While pulse stripping is performed in the bottom edge unit, the multi-channel timing controller sends a start command to the negative pressure induction module. The negative pressure induction module establishes a local low-pressure zone in the central region of the tank through the air intake port located at the top or centerline of the transport tank. This creates a pressure gradient field across the tank cross-section, extending from the high-pressure pulse zone at the edge to the low-pressure induction zone at the center. At this point, the bottom airflow exerts a thrust on the material, while the top negative pressure exerts a pull on the material flow field, forming a push-pull synergistic effect. This pressure gradient forcibly alters the streamline trajectory of the airflow, compelling the stripped edge material to converge towards the central region of the tank along the direction of decreasing pressure, preventing the disordered turbulent diffusion of dust within the tank.

[0040] Central Convergence Conveying Cycle: When the edge material converges to the central traveling wave zone at the bottom of the transport tank under the action of the push-pull flow field, the multi-channel timing controller temporarily shuts down the negative pressure induction module and the edge pulse signal, and reactivates the traveling wave conveying program of the central region pneumatic unit as described in step S300. At this time, the converged material is considered as a newly replenished material layer and is conveyed to the discharge port for discharge under the drive of the central traveling wave. The system can alternately execute the edge stripping convergence and central traveling wave discharge processes until the sensor feedback value indicates that the residual amount has reached an extremely low level. Through the above steps, this invention solves the problem of material retention at irregular geometric boundaries by utilizing flow field control methods.

Claims

1. A method for transporting dry-mixed mortar with low residue and high efficiency, characterized in that, Includes the following steps: S1. System initialization: Set the fluidization maintenance pressure and traveling wave drive pressure according to the material characteristics; S2, global subcritical pre-fluidization, synchronously applying the fluidization maintenance pressure to the entire discrete pneumatic unit array, so that the material is in a quasi-fluid state that eliminates static friction; S3. Time-sequence traveling wave directional conveying: a time-sequence traveling wave control signal is generated to control the units in the discrete pneumatic unit array to apply the traveling wave driving pressure in sequence. The mode switching of the pneumatic elastic variable stiffness one-way valve is used to generate a directional horizontal jet to drive the material to move towards the discharge port. S4. Boundary Residual Convergence Cleaning: When the unloading flow rate is detected to be lower than the preset threshold, the discrete pneumatic unit located at the edge of the transport tank is locked, a pulse-modulated pressure signal is applied, and the negative pressure induction module is activated in coordination to construct a pressure gradient field from the edge to the center, so that the residual material is gathered to the center area and then discharged.

2. The method for transporting dry-mixed mortar with low residue and high efficiency according to claim 1, characterized in that, The pneumatic elastic variable stiffness check valve has a critical deformation threshold pressure. In S2, the fluidization maintenance pressure is less than the critical deformation threshold pressure, the aeroelastic variable stiffness check valve is in the vertical fluidization mode, and the airflow penetrates vertically upward. In S3, when the traveling wave driving pressure is greater than or equal to the critical deformation threshold pressure, the pneumatic elastic variable stiffness check valve undergoes structural deformation and switches to the horizontal conveying mode, and the airflow deflects to form a horizontal jet along the unloading direction.

3. The method for transporting dry-mixed mortar with low residue and high efficiency according to claim 2, characterized in that, In S2, the global subcritical prefluidization specifically includes: Controlling the overall airflow velocity ensures that the generated vertical aerodynamic lift only balances a portion of the effective gravity of the material layer, reduces the internal friction angle between material particles, and limits the airflow velocity to prevent boiling fluidization that leads to macroscopic mixing of materials.

4. The method for transporting dry-mixed mortar with low residue and high efficiency according to claim 2, characterized in that, In S3, the time-series traveling wave directional delivery specifically includes: The discrete pneumatic unit array is logically grouped by row, and the high-pressure excitation window is controlled to move from the direction away from the discharge port to the direction closer to the discharge port according to the preset traveling wave excitation function. The pneumatic unit at the crest of the wave switches to the horizontal conveying mode to push the material, while the pneumatic unit at the trough of the wave remains in the vertical fluidization mode to fill the gap.

5. The method for transporting dry-mixed mortar with low residue and high efficiency according to claim 1, characterized in that, In S4, the discrete pneumatic unit that locks the edge region of the transport tank specifically refers to: Call the pre-stored position coordinate mapping data and select the set of pneumatic units located at the edge and dead corner area of ​​the bottom plate of the transport tank; The directional cut opening of the pneumatic elastic variable stiffness check valve in the pneumatic unit assembly is oriented toward the longitudinal central axis of the transport tank.

6. The method for transporting dry-mixed mortar with low residue and high efficiency according to claim 1, characterized in that, In S4, the applied pulse-modulated pressure signal specifically includes: The discrete pneumatic unit in the locked edge region outputs a pressure signal superimposed with a high-frequency pulsating component, which drives the pneumatic elastic variable stiffness check valve to reciprocate near the critical state of opening and closing, generating mechanical vibration waves to peel off the material attached to the wall.

7. The method for transporting dry-mixed mortar with low residue and high efficiency according to claim 1, characterized in that, In S4, the collaborative activation negative pressure induction module specifically includes: A local low-pressure zone is established above the central area of ​​the transport tank by an internal circulation balance pipe connected to the compressor's suction end. This zone forms a push-pull synergistic convection closed loop with the positive pressure airflow injected by the pneumatic unit in the edge area, which suppresses dust diffusion and induces materials to converge toward the center.

8. The method for transporting dry-mixed mortar with low residue and high efficiency according to claim 7, characterized in that, The boundary residual convergence cleanup also includes loop execution logic: When the edge material converges to the central area under the action of the push-pull flow field, the pulse modulation pressure signal and negative pressure induction module are paused, and the traveling wave conveying program of the central area pneumatic unit is activated to discharge the converged material until the residual amount meets the requirements.

9. The method for transporting dry-mixed mortar with low residue and high efficiency according to claim 4, characterized in that, The traveling wave excitation function adopts a Gaussian distribution function or a trapezoidal distribution function. By adjusting the traveling wave propulsion speed and wave crest width parameters, the area and moving speed of the pneumatic unit in the horizontal conveying mode are controlled.

10. A method for transporting dry-mixed mortar with low residue and high efficiency according to claim 1, characterized in that, The pneumatic elastic variable stiffness one-way valve has a pre-formed directional cut on the surface of its elastic cover plate. When the pressure exceeds the elastic resistance of the material, the directional cut will undergo nonlinear large deformation to open, and will automatically close and self-lock using the elastic rebound force of the material when the pressure disappears.

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