Material mixing and conveying process for preparing dry-mixed mortar

Abstract

The invention discloses a material mixing and conveying process for dry-mixed mortar preparation, and relates to the technical field of material mixing and conveying, the material mixing and conveying process comprises the step S1 of raw material pretreatment, the step S2 of ingredient weighing, the step S3 of dynamic regulation and control, the step S4 of raw material mixing, and the step S5 of finished product packaging. A conveying pipeline is divided into an acceleration section, a turbulent flow section and a steady flow section, the acceleration section increases the airflow speed, the turbulent flow section generates rotational flow, the steady flow section sprays atomized water to form a water film, according to the design, energy consumption is reduced through segmented pressure control, materials are premixed through the turbulent flow section, the adhesion rate of fine powder is increased through water film liquid bridge force, and the segregation index is reduced; furthermore, the materials can be effectively prevented from being layered and separated in the conveying process, the final mixing uniformity is improved, and stable and reliable quality of a dry-mixed mortar product is ensured.

Description

Technical Field

[0001] The invention belongs to the technical field of material mixing and conveying, and in particular relates to a material mixing and conveying process for preparing dry-mix mortar. Background Art

[0002] Dry-mixed mortar is usually called hydraulic cement mixed mortar, which refers to a granular or powdery mortar that is physically mixed in a certain proportion of dried and sieved aggregates (such as quartz sand), inorganic cementitious materials (such as cement) and additives (such as polymers). In the preparation process of dry-mixed mortar, the materials need to be mixed and transported, which is currently mainly achieved through material mixing and conveying equipment.

[0003] In the process of material transportation, pneumatic conveying can be used, which can use the energy of gas to transport solid particulate materials. Pneumatic conveying generally uses constant air pressure for transportation throughout the process. However, constant air pressure will cause high energy consumption and easy segregation of raw materials, resulting in uneven material mixing. In response to the above problems, the following solutions are proposed. Summary of the invention

[0004] The purpose of the present invention is to provide a material mixing and conveying process for preparing dry-mix mortar. Through active flow control in the conveying stage, forward optimization of the preparation process is achieved, and the problem of stratification and segregation in the existing material mixing and conveying process, which leads to insufficient final mixing uniformity, is solved.

[0005] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0006] The present invention is a material mixing and conveying process for preparing dry-mix mortar, comprising:

[0007] Step S1, raw material pretreatment: processing sand and gravel aggregates and powder by drying, screening, iron removal and purification operations;

[0008] Step S2, ingredient weighing: adopting the coordinated control of the three-level metering system of static bin metering, dynamic belt scale and loss-in-weight correction to weigh various raw materials;

[0009] Step S3, dynamic control: dynamically control pneumatic conveying through pipeline partition structure, sensor system, dynamic control actuator and digital twin system;

[0010] Step S4, raw material mixing: using a mixer to achieve material mixing through mechanical structure, mixing enhancement measures and ultrasonic atomization;

[0011] Step S5, finished product packaging: the packaging machine automatically identifies the specifications of the valve bag, sets up a dust removal system, and uses a cyclone, pulse bag and activated carbon adsorption three-stage filtration;

[0012] The step S3, dynamic control, specifically includes a pipeline partition structure, a sensor system, a dynamic control actuator and a digital system.

[0013] Preferably, the pipeline partition structure is specifically divided into an acceleration section, a turbulent flow section and a steady flow section;

[0014] The acceleration section is 8 meters long and is designed as a tapered venturi tube with a contraction angle of 7°, an inlet diameter of Φ300mm, and an outlet diameter of Φ200mm;

[0015] The turbulent section is 6 meters long and has a built-in spiral guide vane with an adjustable lead range of 0.5-1.2m. The surface of the guide vane is sprayed with a WC-Co wear-resistant coating;

[0016] The flow stabilizing section is 4 meters long and is an expansion tube structure with an expansion angle of 3°. It is equipped with a porous medium flow stabilizing plate with an aperture of Φ5 mm and an opening rate of 40%.

[0017] Preferably, the sensing system includes a differential pressure sensor, material flow rate monitoring and temperature monitoring;

[0018] The differential pressure sensor adopts a differential pressure transmitter and is installed in an array on the outer wall of the pipeline with a spacing of 1.5m;

[0019] The material flow rate monitoring adopts an insertion type microwave Doppler flowmeter, and the material flow state database is established through EDEM discrete element simulation;

[0020] The temperature monitoring adopts PT100 platinum resistance.

[0021] Preferably, the dynamic control actuator can compare the sensor data with the database in real time and automatically adjust the parameters of each pipeline section, as follows:

[0022] Air pressure regulation in the acceleration stage: Use a variable frequency screw compressor to adjust the compressor frequency in real time based on the feedback from the pressure difference sensor through a fuzzy control algorithm to adjust the air pressure within 0.25-0.35MPa;

[0023] Swirl control in turbulent section: a swirl generator is introduced, which consists of 6 sets of adjustable guide vanes, and the guide vane angle is driven by a servo motor;

[0024] The guide vane angle is related to the speed: when the angle is 30°, the upper speed limit is 150rpm; when the angle is 60°, the upper speed limit is 300rpm;

[0025] Steady flow section: reduce the air pressure to 0.15MPa and inject atomized water, the atomized water ≤0.1L / min, the steady flow section adopts a double-fluid atomizing nozzle, and the water volume is controlled by a micro-metering pump.

[0026] Preferably, the digital system specifically includes simulation modeling, database construction and real-time control;

[0027] The simulation modeling is based on EDEM-Fluent coupling simulation, and the gas-solid two-phase flow model of 16 typical materials is established. The constructed database contains flow characteristic data of various working conditions;

[0028] The real-time control is specifically as follows: sensor data is collected every 30 ms, characteristic values ​​are extracted, the closest working condition model is matched in the database through the KNN algorithm, and adjustment instructions are output to the actuator to complete closed-loop control.

[0029] Preferably, in the step S2, the static bin measurement in the ingredient weighing adopts a cantilever beam weighing sensor, the static bin body is designed as an inverted pyramid structure, and the amount of pre-stored materials in the static bin is controlled at 80% of the rated capacity.

[0030] Preferably, in step S2, the dynamic belt scale in the ingredient weighing is equipped with a laser velocimeter and a matrix weighing roller, and the collected speed and weight signals are fused through a Kalman filter algorithm to dynamically compensate for the belt jitter error.

[0031] Preferably, the weight loss correction in the step S2, ingredient weighing, adopts a PID-Smith predictor control algorithm, and feeds are made through a feeding bin, the feeding bin is equipped with a double screw feeder, the double screw feeder has a coarse adjustment of Φ200mm + fine adjustment of Φ80mm, and the correction rate range is 0.1-5kg / s.

[0032] Preferably, in step S4, the mechanical structure of the mixer in the raw material mixing adopts the mode of cylinder rotation and internal blade reverse motion, and the cylinder is a W-shaped double cone structure with a volume of 3m 3 The speed range is 8-15rpm, the internal blades are arranged in a three-axis staggered manner, the blade angle is 45°, and the reverse speed range is 25-35rpm.

[0033] Preferably, in step S4, the mixing strengthening measure in the raw material mixing is to set a baffle on the inner wall of the cylinder, the baffle height is 50 mm, the spacing is 200 mm, and a retractable scraper is installed at the end of the blade;

[0034] The ultrasonic atomization system starts the ultrasonic atomization nozzle when adding the modifier, the atomization particle size is ≤20μm, the transducer frequency is 28kHz, the atomization volume is 0-5L / h continuously adjustable, and the atomization chamber is designed as a Venturi structure.

[0035] The present invention has the following beneficial effects:

[0036] 1. In the process of material transportation, the present invention uses pneumatic conveying for dynamic regulation, and divides the conveying pipeline into an acceleration section, a turbulent section and a steady flow section. The acceleration section increases the gas velocity, the turbulent section generates a swirl, and the steady flow section sprays atomized water to form a water film. The energy consumption is reduced by segmented pressure control, the material is pre-mixed in the turbulent section, the liquid bridge force of the water film makes the adhesion rate of fine powder increased, and the segregation index decreased, thereby effectively preventing the material from being stratified and segregated during transportation, improving the final mixing uniformity, and ensuring the stable and reliable quality of the dry-mixed mortar product.

[0037] 2. The present invention adopts a high-precision cantilever beam weighing sensor and an inverted pyramid silo structure to accurately measure static materials. The dynamic belt scale uses a high-resolution laser velocimeter and a matrix weighing roller, combined with a Kalman filter algorithm, to accurately measure dynamic materials. The double-screw feeder and PID-Smith predictor control algorithm in the loss-in-weight correction link can accurately replenish materials and solve the problem of large lag and overshoot, ensuring the accurate proportion of each raw material, reducing manual intervention and errors, improving production efficiency, and ensuring that the quality of different batches of dry-mixed mortar is stable and consistent.

[0038] 3. The present invention can enhance the tumbling mixing effect of materials through the W-shaped double-cone structure cylinder and three-axis staggered blades of the mixer, combined with adjustable speed. The baffles on the inner wall of the cylinder strengthen radial mixing. The paddle scrapers automatically clean the accumulated materials on the cylinder wall to avoid the influence of material residue on the mixing uniformity. The Venturi structure atomization chamber of the ultrasonic atomization system allows the droplets to fully contact the material. The synergistic effect of various designs can improve the mixing uniformity, ensure the uniform distribution of the components of the dry-mixed mortar, and effectively improve the product performance and use effect.

[0039] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0041] Figure 1 The present invention is a schematic diagram of the process of material mixing and conveying for preparing dry-mix mortar. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] See also Figure 1 As shown, the present invention is a material mixing and conveying process for preparing dry-mixed mortar, comprising:

[0044] Step S1, raw material pretreatment: processing sand and gravel aggregates and powder by drying, screening, iron removal and purification operations;

[0045] Step S2, ingredient weighing: adopting the coordinated control of the three-level metering system of static bin metering, dynamic belt scale and loss-in-weight correction to weigh various raw materials;

[0046] Step S3, dynamic control: dynamically control pneumatic conveying through pipeline partition structure, sensor system, dynamic control actuator and digital twin system;

[0047] Step S4, raw material mixing: using a mixer to achieve material mixing through mechanical structure, mixing enhancement measures and ultrasonic atomization;

[0048] Step S5, finished product packaging: the packaging machine automatically identifies the specifications of the valve bag, sets up a dust removal system, and uses a cyclone, pulse bag and activated carbon adsorption three-stage filtration;

[0049] Step S3, dynamic control specifically includes pipeline partition structure, sensor system, dynamic control actuator and digital system.

[0050] The pipeline partition structure is specifically divided into acceleration section, turbulent section and steady flow section;

[0051] The acceleration section is 8 meters long and is designed as a tapered Venturi tube with a contraction angle of 7°, an inlet diameter of Φ300mm, and an outlet diameter of Φ200mm;

[0052] The turbulent section is 6 meters long and has a built-in spiral guide vane with an adjustable lead range of 0.5-1.2m. The surface of the guide vane is sprayed with WC-Co wear-resistant coating;

[0053] The flow stabilizing section is 4 meters long and is an expansion tube structure with an expansion angle of 3°. It is equipped with a porous medium flow stabilizing plate with an aperture of Φ5mm and an opening rate of 40%.

[0054] The sensing system includes differential pressure sensors, material flow rate monitoring and temperature monitoring;

[0055] The differential pressure sensor uses a differential pressure transmitter and is installed in an array on the outer wall of the pipeline with a spacing of 1.5m;

[0056] The material flow rate is monitored by an insertion type microwave Doppler flowmeter, and the material flow state database is established through EDEM discrete element simulation;

[0057] The temperature is monitored by PT100 platinum resistance.

[0058] The dynamic control actuator can compare the sensor data with the database in real time and automatically adjust the parameters of each pipeline section, as follows:

[0059] Air pressure regulation in the acceleration stage: Use a variable frequency screw compressor to adjust the compressor frequency in real time based on the feedback from the pressure difference sensor through a fuzzy control algorithm to adjust the air pressure within 0.25-0.35MPa;

[0060] Swirl control in turbulent section: a swirl generator is introduced, which consists of 6 sets of adjustable guide vanes, and the guide vane angle is driven by a servo motor;

[0061] The guide vane angle is related to the speed: when the angle is 30°, the upper speed limit is 150rpm; when the angle is 60°, the upper speed limit is 300rpm;

[0062] Steady flow section: reduce the air pressure to 0.15MPa and inject atomized water, the atomized water ≤0.1L / min, the steady flow section adopts a double-fluid atomizing nozzle, and the water volume is controlled by a micro-metering pump.

[0063] Digital systems specifically include simulation modeling, database construction, and real-time control;

[0064] The simulation modeling is based on EDEM-Fluent coupling simulation, and the gas-solid two-phase flow model of 16 typical materials is established. The constructed database contains the flow characteristic data of various working conditions;

[0065] Real-time control is as follows: sensor data is collected every 30ms, characteristic values ​​are extracted, the closest working condition model is matched in the database through the KNN algorithm, and adjustment instructions are output to the actuator to complete closed-loop control.

[0066] Step S2: In the weighing of ingredients, the static bin is measured by a cantilever beam weighing sensor, the static bin body is designed as an inverted pyramid structure, and the amount of pre-stored materials in the static bin is controlled at 80% of the rated capacity.

[0067] Step S2: In the batching weighing, the dynamic belt scale is equipped with a laser velocimeter and a matrix weighing roller. The collected speed and weight signals are fused through the Kalman filter algorithm to dynamically compensate for the belt jitter error.

[0068] Step S2, the weight loss correction in the batching weighing adopts the PID-Smith predictor control algorithm, and the material is replenished through the replenishing bin. The replenishing bin is equipped with a double screw feeder. The double screw feeder has a coarse adjustment of Φ200mm + fine adjustment of Φ80mm, and the correction rate range is 0.1-5kg / s.

[0069] Step S4: The mechanical structure of the mixer in the raw material mixing process adopts the method of cylinder rotation and internal blade reverse motion. The cylinder is a W-shaped double cone structure with a volume of 3m 3 The speed range is 8-15rpm. The internal blades are arranged in a three-axis staggered manner, the blade angle is 45°, and the reverse speed range is 25-35rpm.

[0070] Step S4: During the mixing of the raw materials, a baffle is provided on the inner wall of the cylinder, the height of the baffle is 50 mm, the spacing is 200 mm, and a retractable scraper is installed at the end of the blade;

[0071] The ultrasonic atomization system starts the ultrasonic atomization nozzle when adding the modifier. The atomization particle size is ≤20μm, the transducer frequency is 28kHz, the atomization volume is 0-5L / h continuously adjustable, and the atomization chamber is designed as a Venturi structure.

[0072] A specific application of this embodiment is:

[0073] Step S1, raw material pretreatment specifically includes:

[0074] Sand and gravel aggregate processing: The drying system adopts a three-pass drum structure, and the hot air temperature is controlled in stages (300°C at the inlet → 80°C at the outlet). The moisture content is monitored in real time by an infrared moisture meter to ensure that there is no thermal damage to the aggregate surface after drying. The three-stage gradient cooling avoids the cracking of the aggregate surface and can effectively reduce the fluctuation of moisture content.

[0075] The screening machine is equipped with a multi-layer resonant screen (4 layers of SS304 stainless steel sieve plates, with a pore size gradient of 5mm / 3mm / 1mm / 0.6mm). Aggregates of different particle sizes enter independent silos through pneumatic distribution valves.

[0076] Powder purification system: The iron remover adopts a permanent magnetic drum + electromagnetic suspension double-stage design, and the magnetic field strength reaches 1200Gs and 8000Gs respectively;

[0077] The vibrating screen is equipped with a polymer nylon screen (adjustable mesh size 80-120 mesh), and the screen body is equipped with an inclination sensor to achieve automatic screen cleaning;

[0078] Anti-arching high-frequency micro-vibration device:

[0079] Structural design: A piezoelectric ceramic vibrator array (spacing 200mm×200mm) is installed on the outer wall of the cone section of the silo, and the vibrator surface is covered with a wear-resistant silicon carbide coating;

[0080] Working Mode:

[0081] Normal mode: 50Hz low-frequency vibration (amplitude 0.5mm), continuous prevention of bridging;

[0082] Emergency mode: When the material level meter detects that the material is stagnant, it starts a 100Hz high-frequency pulse (amplitude 2mm, duration 3s);

[0083] Control logic: Establish a vibration parameter database through material fluidity testing to automatically match the critical vibration frequency of different materials;

[0084] Step S2, weighing ingredients specifically includes:

[0085] Static silo metering: cantilever beam weighing sensor (accuracy 0.05% FS) is used, and the silo is designed as an inverted pyramid structure to reduce dead zone; the pre-stored material volume is controlled at 80% of the rated capacity to avoid material compaction affecting accuracy;

[0086] Dynamic belt scale: equipped with high-resolution laser velocimeter (sampling frequency 1kHz) and matrix weighing roller (8 sets of strain gauge layout); the speed and weight signals collected by the sensor are fused through Kalman filter algorithm to dynamically compensate for belt jitter error, further improving the overall accuracy of batching;

[0087] Loss-in-weight correction: The feeding bin is equipped with a double screw feeder (coarse adjustment Φ200mm, fine adjustment Φ80mm), and the correction rate can be adjusted in the range of 0.1-5kg / s; the PID-Smith predictor control algorithm is adopted to solve the overshoot problem of the large lag system; the feeding rate is automatically adjusted according to the difference in sand and gravel fluidity, which can improve the consistency of batches;

[0088] Step S3, dynamic control specifically includes:

[0089] Pipeline partition structure and sensor system:

[0090] Acceleration section (length 6m): tapered Venturi tube design, contraction angle 7°, inlet diameter Φ300mm→exit Φ200mm;

[0091] Turbulent section (length 8m): built-in spiral guide vane (adjustable lead range 0.5-1.2m), the guide vane surface is sprayed with WC-Co wear-resistant coating;

[0092] Flow stabilization section (length 4m): expansion tube structure (expansion angle 3°) with porous medium flow stabilization plate (aperture Φ5mm, opening rate 40%);

[0093] Sensor Configuration:

[0094] Differential pressure sensor: using differential pressure transmitter (range 0-50kPa, accuracy ±0.1%FS);

[0095] Material flow rate monitoring: Insertion type microwave Doppler flowmeter (frequency 24GHz);

[0096] Temperature monitoring: PT100 platinum resistance (measuring range -50~200℃);

[0097] Dynamic control actuator:

[0098] Acceleration section air pressure regulation: Use variable frequency screw compressor (power 55kW, exhaust volume 10m 3 / min);

[0099] According to the feedback from the differential pressure sensor, the compressor frequency (30-50Hz) is adjusted in real time through the fuzzy control algorithm;

[0100] Swirl control in turbulent section: The swirl generator consists of 6 sets of adjustable guide vanes, and the guide vane angle is driven by a servo motor (adjustment accuracy 0.1°);

[0101] The guide vane angle is related to the speed: the upper speed limit is 150rpm when the angle is 30°, and can reach 300rpm when the angle is 60°;

[0102] Steady flow section atomization system: using dual-fluid atomization nozzle (compressed air pressure 0.4MPa, water pressure 0.2MPa);

[0103] Water volume control: micro metering pump (flow rate 0-0.12L / min adjustable, resolution 0.001L);

[0104] Digital Twin System:

[0105] Simulation modeling: Based on EDEM-Fluent coupling simulation, gas-solid two-phase flow models of 16 typical materials were established;

[0106] Database construction: Contains flow characteristic data of 256 working conditions (pressure gradient, particle velocity distribution, concentration field, etc.);

[0107] Real-time control: collect sensor data every 30ms and extract characteristic values ​​(pressure fluctuation variance, flow rate standard deviation, etc.); match the closest working condition model in the database through the KNN algorithm; output adjustment instructions to the actuator to complete closed-loop control;

[0108] The power consumption can be reduced by segmented pressure control, and pretreatment can be performed during transportation.

[0109] Step S4, mixing raw materials specifically includes:

[0110] Mechanical structure: double motion mixer (rotating cylinder + reverse motion of internal blades);

[0111] Cylinder: W-shaped double cone structure, volume 3m 3 , speed adjustable from 8-15rpm;

[0112] Internal propellers: three-axis staggered arrangement, propeller angle 45°, reverse speed 25-35rpm;

[0113] Mixed reinforcement measures:

[0114] Baffles (50mm in height and 200mm in spacing) are installed on the inner wall of the cylinder to enhance radial mixing; retractable scrapers are installed at the end of the blades to automatically clean the accumulated material on the cylinder wall;

[0115] Ultrasonic atomization system:

[0116] The transducer frequency is 28kHz, and the atomization volume is continuously adjustable from 0 to 5L / h. The atomization chamber is designed as a Venturi structure to ensure that the droplets are fully in contact with the material flow.

[0117] Step S5, finished product packaging: the packaging machine automatically identifies the specifications of the valve bag, sets up a dust removal system, and uses a cyclone, pulse bag and activated carbon adsorption three-stage filtration;

[0118] Workflow:

[0119] The wet sand is dehydrated by the three-pass drum dryer with gradient temperature control. After classification and screening, the aggregate enters the intelligent silo equipped with a piezoelectric ceramic high-frequency micro-vibration device to reduce the risk of arching. After the powder is purified by magnetic separation and vibration screen, it is proportioned with the aggregate through the batching system. The pneumatic conveying dynamic control system divides the pipeline into an acceleration section, a turbulent section and a steady flow section. The Venturi acceleration section uses a variable frequency compressor to achieve initial mixing of materials. The adjustable guide vanes in the turbulent section generate a cyclonic flow field to promote sand and powder collision and premixing. The atomized water film in the steady flow section enhances the adhesion of fine powder, making the conveying process The premixing process is completed, the power consumption per ton of material is reduced, and the segregation index is also reduced. The premix then enters the mixer, and the W-shaped cylinder and reverse blades form a three-dimensional mixing trajectory. The baffle and ultrasonic atomizer are used to improve the uniformity of additive dispersion. The final product is filled by the packaging machine, and the dust emission is controlled by pulse bag and activated carbon three-stage dust removal throughout the process. This process reduces the fluctuation range of compressive strength through the coordination of conveying premixing, dynamic regulation and intelligent compensation, while also reducing the comprehensive energy consumption per ton of product and reducing dust emissions.

[0120] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0121] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A material mixing and conveying process for preparing dry-mix mortar, characterized in that: The material mixing and conveying process comprises the following steps: Step S1, raw material pretreatment: processing sand and gravel aggregates and powder by drying, screening, iron removal and purification operations; Step S2, ingredient weighing: adopting the coordinated control of the three-level metering system of static bin metering, dynamic belt scale and loss-in-weight correction to weigh various raw materials; Step S3, dynamic control: dynamically control pneumatic conveying through pipeline partition structure, sensor system, dynamic control actuator and digital twin system; Step S4, raw material mixing: using a mixer to achieve material mixing through mechanical structure, mixing enhancement measures and ultrasonic atomization; Step S5, finished product packaging: the packaging machine automatically identifies the specifications of the valve bag, sets up a dust removal system, and uses a cyclone, pulse bag and activated carbon adsorption three-stage filtration; The step S3, dynamic control, specifically includes a pipeline partition structure, a sensor system, a dynamic control actuator and a digital system.

2. A material mixing and conveying process for preparing dry-mixed mortar according to claim 1, characterized in that: The pipeline partition structure is specifically divided into an acceleration section, a turbulent flow section and a steady flow section; The acceleration section is 8 meters long and is designed as a tapered venturi tube with a contraction angle of 7°, an inlet diameter of Φ300mm, and an outlet diameter of Φ200mm; The turbulent section is 6 meters long and has a built-in spiral guide vane with an adjustable lead range of 0.5-1.2m. The surface of the guide vane is sprayed with a WC-Co wear-resistant coating; The flow stabilizing section is 4 meters long and is an expansion tube structure with an expansion angle of 3°. It is equipped with a porous medium flow stabilizing plate with an aperture of Φ5 mm and an opening rate of 40%.

3. A material mixing and conveying process for preparing dry-mixed mortar according to claim 2, characterized in that: The sensing system includes a differential pressure sensor, material flow rate monitoring and temperature monitoring; The differential pressure sensor adopts a differential pressure transmitter and is installed in an array on the outer wall of the pipeline with a spacing of 1.5m; The material flow rate monitoring adopts an insertion type microwave Doppler flowmeter, and the material flow state database is established through EDEM discrete element simulation; The temperature monitoring adopts PT100 platinum resistance.

4. A material mixing and conveying process for preparing dry-mixed mortar according to claim 1, characterized in that: The dynamic control actuator can compare the sensor data with the database in real time and automatically adjust the parameters of each pipeline section, as follows: Air pressure regulation in the acceleration stage: Use a variable frequency screw compressor to adjust the compressor frequency in real time based on the feedback from the pressure difference sensor through a fuzzy control algorithm to adjust the air pressure within 0.25-0.35MPa; Swirl control in turbulent section: a swirl generator is introduced, which consists of 6 sets of adjustable guide vanes, and the guide vane angle is driven by a servo motor; The guide vane angle is related to the speed: when the angle is 30°, the upper speed limit is 150rpm; when the angle is 60°, the upper speed limit is 300rpm; Steady flow section: reduce the air pressure to 0.15MPa and inject atomized water, the atomized water ≤0.1L / min, the steady flow section adopts a double-fluid atomizing nozzle, and the water volume is controlled by a micro-metering pump.

5. The material mixing and conveying process for preparing dry-mixed mortar according to claim 1, characterized in that: The digital system specifically includes simulation modeling, database construction and real-time control; The simulation modeling is based on EDEM-Fluent coupling simulation, and the gas-solid two-phase flow model of 16 typical materials is established. The constructed database contains flow characteristic data of various working conditions; The real-time control is specifically as follows: sensor data is collected every 30 ms, characteristic values ​​are extracted, the closest working condition model is matched in the database through the KNN algorithm, and adjustment instructions are output to the actuator to complete closed-loop control.

6. A material mixing and conveying process for preparing dry-mixed mortar according to claim 1, characterized in that: In the step S2, the static bin measurement in the batching weighing adopts a cantilever beam weighing sensor, the static bin body is designed as an inverted pyramid structure, and the pre-stored material amount in the static bin is controlled at 80% of the rated capacity.

7. The material mixing and conveying process for preparing dry-mixed mortar according to claim 1, characterized in that: In the step S2, the dynamic belt scale in the ingredient weighing is equipped with a laser velocimeter and a matrix weighing roller, and the collected speed and weight signals are fused through the Kalman filter algorithm to dynamically compensate for the belt jitter error.

8. The material mixing and conveying process for preparing dry-mixed mortar according to claim 1, characterized in that: The step S2, the weight loss correction in the ingredient weighing adopts the PID-Smith predictor control algorithm, and the material is replenished through the replenishing bin, the replenishing bin is equipped with a double screw feeder, the double screw feeder has a coarse adjustment of Φ200mm + fine adjustment of Φ80mm, and the correction rate range is 0.1-5kg / s.

9. The material mixing and conveying process for preparing dry-mixed mortar according to claim 1, characterized in that: The mechanical structure of the mixer in step S4, raw material mixing, adopts the method of cylinder rotation and internal blade reverse motion. The cylinder is a W-shaped double cone structure with a volume of 3m 3 The speed range is 8-15rpm, the internal blades are arranged in a three-axis staggered manner, the blade angle is 45°, and the reverse speed range is 25-35rpm.

10. The material mixing and conveying process for preparing dry-mixed mortar according to claim 1, characterized in that: In step S4, the mixing strengthening measure in the raw material mixing is to set a baffle on the inner wall of the cylinder, the baffle height is 50mm, the spacing is 200mm, and a retractable scraper is installed at the end of the blade; The ultrasonic atomization system starts the ultrasonic atomization nozzle when adding the modifier, the atomization particle size is ≤20μm, the transducer frequency is 28kHz, the atomization volume is 0-5L / h continuously adjustable, and the atomization chamber is designed as a Venturi structure.

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