Powder additive conveying system

Abstract

The invention discloses a powder additive conveying system which comprises a main body structure composed of a stirring barrel assembly, a storage barrel assembly, a pumping mechanism and a plurality of groups of conveying pipes, a metering type feeding hopper and a liquid quantitative injection valve are arranged at the top of the stirring barrel assembly, and the bottom of the stirring barrel assembly is communicated with the storage barrel assembly through a pneumatic stop valve; the storage barrel assembly is connected with a conveying pipe set with an atomizing nozzle at the tail end through a pumping mechanism, the stirring device is of a double-shaft differential structure, an inner-layer stirring shaft is provided with variable-pitch propeller blades, an outer-layer stirring shaft is provided with an annular flow guide plate for adjusting the inclination angle, and a rotating speed difference is formed through driving of an independent servo motor so as to generate a three-dimensional shear flow field. In the conveying control device, an electromagnetic valve adopts a pulse width modulation control mode and is integrated with a self-cleaning flow channel, a flow regulator is internally provided with a double-turbine flowmeter to form a redundancy measurement mechanism, and a monitoring module is integrated with a capacitive liquid level sensor, an infrared spectrum concentration sensor and a non-contact temperature sensor array.

Description

Technical Field

[0001] This invention relates to the textile industry, and in particular to a powder additive delivery system. Background Technology

[0002] In industrial fields such as textile printing and dyeing, chemical synthesis and materials processing, the level of automation of auxiliary agent conveying systems is directly related to production efficiency and quality control. Traditional conveying systems generally use simple metering devices to complete the mixing ratio of powder and liquid additives. Material transfer relies on gravity feeding or simple valve control. The stirring device mostly adopts a single-shaft structure. The layout of conveying pipelines and the design of control modules are relatively simple. The monitoring system mainly uses discrete parameter acquisition. When dealing with the high-precision conveying requirements of high viscosity and multi-component powder additives, this kind of traditional architecture has gradually exposed common technical bottlenecks such as insufficient mixing uniformity, lagging process control and frequent equipment maintenance.

[0003] Existing powder additive conveying systems suffer from multiple structural defects: their feeding modules lack automated proportioning mechanisms, operational errors easily lead to batch-to-batch quality fluctuations, and gravity feeding methods often cause metering inaccuracies due to material bridging; the single-axis co-rotating structure used in the stirring device is prone to stratification and segregation due to uneven shear force distribution when handling high-viscosity materials, and the lack of a variable pitch propulsion structure and flow guiding mechanism further restricts the formation of an axial-radial composite flow field; the conveying pipelines mostly adopt a segmented connection design, which not only increases the risk of material residue, but also makes it difficult for the single-channel layout to meet the needs of multi-station synchronous feeding; the control valves lack self-cleaning functions, and powder crystallization and clogging problems occur frequently; single flowmeter configuration can easily cause unstable spraying volume under abnormal operating conditions; the monitoring system relies too much on contact sensors, resulting in high maintenance costs and weak anti-interference capabilities; traditional PID control algorithms have insufficient dynamic compensation capabilities for raw material characteristic fluctuations and environmental interference; and multi-parameter collaborative control has significant lag. Therefore, a powder additive conveying system is proposed. Summary of the Invention

[0004] This invention provides the following technical solution: a powder additive delivery system, comprising: System main structure: The system includes a mixing tank assembly, a storage tank assembly, a pumping mechanism, and a delivery pipe. The mixing tank assembly is equipped with a metering feed hopper and a liquid metering injection valve at the top, and is connected to the storage tank assembly at the bottom via a first pipe, which is equipped with a pneumatic shut-off valve. The storage tank assembly is equipped with a second pipe at the bottom, and the end of the second pipe is connected to the inlet of the pumping mechanism. The outlet of the pumping mechanism is connected to multiple sets of delivery pipes via a third pipe, and the end of each set of delivery pipes is equipped with an atomizing nozzle that connects to the spraying station of the stenter. Stirring device: The mixing tank assembly includes a dual-shaft differential speed mixing mechanism, comprising an inner and outer mixing shaft mounted coaxially; the inner mixing shaft is equipped with variable pitch spiral mixing blades, and the outer mixing shaft is equipped with an annular guide plate for adjusting the tilt angle; the speed difference between the two shafts is controlled by independent servo motors. Conveying control device: Each set of delivery pipes is equipped with a solenoid valve and a flow regulator; the solenoid valve adopts pulse width modulation control and has a self-cleaning flow channel inside; the flow regulator has a built-in dual turbine flow meter; Monitoring and Feedback Module: The mixing tank assembly includes a capacitive liquid level sensor, an infrared spectral concentration sensor, and a non-contact temperature sensor array installed on its inner wall; the storage tank assembly includes a pressure sensor and a vibration monitoring sensor. The monitoring data is transmitted to the central controller in real time via a dual-redundant CAN bus. The controller has a built-in adaptive fuzzy PID algorithm module and a feedforward compensation unit. Safety protection devices: The pumping mechanism inlet is equipped with a three-stage filtration system: the first stage is a stainless steel filter, the second stage is a permanent magnet separator, and the third stage is a polytetrafluoroethylene filter element; the top of the storage tank assembly is equipped with a dual-redundant structure of a mechanical safety valve and an electronic pressure relief valve.

[0005] Raw material mixing and temporary storage stage: Solid powder additives are added in a preset ratio through the metering hopper at the top of the mixing tank assembly, and liquid additives are injected synchronously through the liquid metering injection valve to form an initial mixture. When the dual-shaft differential speed stirring mechanism is started, the inner stirring shaft drives the variable pitch spiral stirring blades to push the material axially at high speed, while the outer stirring shaft rotates in the opposite direction at low speed to drive the annular guide plate with adjustable tilt angle to form a radial shear flow field. The three-dimensional turbulent mixing effect is generated through the speed difference. During the mixing process, a capacitive liquid level sensor monitors the material height in real time, an infrared spectral concentration sensor detects the uniformity of the components, and a non-contact temperature sensor array monitors the temperature distribution. The data is transmitted to the central controller via a dual-redundant CAN bus. After the mixture meets the standard, the pneumatic shut-off valve opens, and the mixed material flows into the storage tank assembly through the first pipe; Stabilized delivery and precise distribution stage: Pressure sensors inside the storage tank assembly monitor the static pressure of the material, vibration monitoring sensors detect the risk of sedimentation and stratification, and the data is fed back to the central controller to trigger the feedforward compensation unit. When the pumping mechanism is started, the material enters the pump body through the second pipeline and passes through the three-stage filtration assembly to complete the coarse filtration of the stainless steel filter screen, the impurity removal of the permanent magnet iron separator, and the fine filtration of the polytetrafluoroethylene filter element in sequence. The pumped material is distributed to multiple sets of conveying pipes via a third pipeline. The solenoid valves of each set of conveying pipes adopt pulse width modulation control. By adjusting the duty cycle, the flow pulse is opened and closed. Combined with the bidirectional metering function of the dual turbine flow meter in the flow regulator, the instantaneous flow is precisely controlled. The material ultimately passes through the atomizing nozzle; Dynamic optimization and security assurance phase: The central controller has a built-in adaptive fuzzy PID algorithm module that adjusts the stirring speed, pumping pressure and solenoid valve opening in real time based on monitoring data to form a closed-loop control. When the pressure inside the storage tank assembly is abnormal, the mechanical safety valve and the electronic pressure relief valve work together to release pressure. The solenoid valve's self-cleaning flow channel automatically removes crystals through reverse pulsed airflow, maintaining long-term operational stability.

[0006] Preferably, the movement control of the solenoid valve core adopts a three-segment speed curve planning, with a sinusoidal acceleration curve for the opening stage and a trapezoidal deceleration curve for the closing stage; the surface of the chamfered transition structure of the valve seat is provided with a hard anodized layer, and the thickness of the anodized layer is positively correlated with the nominal pressure of the valve body.

[0007] The solenoid valve core motion control adopts a three-segment speed curve planning, and the specific implementation steps are as follows: In the opening stage, the drive circuit outputs a control signal according to the preset sinusoidal acceleration curve, and realizes the uniform acceleration start of the valve core through current closed-loop control; in the intermediate stage, it maintains a uniform speed motion state, and the position sensor provides real-time feedback of the valve core displacement data; in the closing stage, it switches to a trapezoidal deceleration curve, and achieves linear deceleration by dynamically adjusting the slope of the drive voltage until the valve core is completely closed. The surface of the valve seat chamfer transition structure forms a hard anodized layer through a micro-arc oxidation process. The thickness of the oxide layer is matched according to the nominal pressure parameter table of the valve body, and pulse current density control technology is used to ensure the uniformity of the film layer.

[0008] Preferably, the automatic calibration module of the infrared spectral concentration sensor is equipped with an ambient light shielding unit. The shielding unit uses a dual-frequency rotating chopper, and the chopping frequency maintains a synchronous phase difference with the light source modulation frequency.

[0009] When the automatic calibration module of the infrared spectral concentration sensor performs ambient light shielding, the dual-frequency rotary chopper operates in synchronous phase difference mode: the main control unit generates a reference pulse signal according to the modulation frequency of the light source, drives the motor to rotate the dual-frequency chopper, and monitors the position of the chopper in real time through the photoelectric encoder, so that the opening period of the light-transmitting window and the flashing period of the light source maintain a certain phase difference, forming a physical shielding effect.

[0010] Preferably, the annular guide plate on the surface of the outer stirring shaft of the dual-shaft differential stirring mechanism is dynamically adjusted in circumferential tilt angle by an electric adjustment mechanism. The adjustment mechanism has a built-in angle encoder and an independent servo motor to form a closed-loop control loop. A dead zone compensation module is set in the control loop to eliminate the angle deviation caused by gear backlash.

[0011] The adjustment process of the outer stirring shaft guide plate of the dual-shaft differential stirring mechanism is as follows: The independent servo motor drives the ball screw through the planetary reducer to convert the rotational motion into the circumferential tilting motion of the guide plate. The angle encoder collects the current tilt angle in real time and feeds it back to the PID controller. When the deviation between the actual angle and the set value exceeds the dead zone threshold, the control loop triggers the compensation algorithm to eliminate the angle lag caused by the gear backlash by adjusting the motor pulse duty cycle.

[0012] Preferably, the electric adjustment mechanism adopts a planetary gear reducer and ball screw combined transmission structure, and the ball screw lead is linearly proportional to the adjustment range of the guide plate. The proportional coefficient is experimentally calibrated and stored in the non-volatile memory of the central controller.

[0013] The electric adjustment mechanism uses a combination of planetary gear reducer and ball screw transmission: the planetary reducer converts the high-speed input of the servo motor into low-speed, high-torque output, and the ball screw converts the rotational motion into linear displacement. The tilt angle of the guide plate is precisely controlled through the linear relationship between the lead of the screw and the displacement of the nut. The central controller calls the corresponding parameters according to the proportional coefficient library calibrated in the experiment to complete the angle-displacement conversion calculation.

[0014] Preferably, the pumping mechanism adopts a positive displacement gear pump, with pressure balancing valves installed at the pump body inlet and outlet, and the pump shaft seal adopts a double-end mechanical seal structure. The sealing surface is provided with a spiral groove dynamic pressure lubrication structure, and the lubricating oil circuit and the pumping medium are physically separated by a ceramic isolation sleeve.

[0015] When the positive displacement gear pump is running, the pressure balance valve at the inlet and outlet of the pump body senses the pressure difference through an elastic diaphragm. When the inlet pressure fluctuates, the diaphragm deforms and drives the valve core to open the compensation channel to maintain a constant pressure difference between the inlet and outlet. The double-end mechanical seal adopts a cartridge structure. The sealing end face is supplied with oil by a spiral groove dynamic pressure lubrication system. The lubricating oil forms a physical barrier with the pumping medium through a ceramic isolation sleeve to prevent the medium from penetrating into the bearing area.

[0016] Preferably, the gear pair of the positive displacement gear pump is carburized and quenched, and the gear meshing clearance is monitored online by a laser rangefinder. When the clearance exceeds a certain level, an audible and visual alarm device is triggered.

[0017] The online monitoring process for positive displacement gear pump gear pairs is as follows: A laser rangefinder emits a red laser of a certain wavelength, which is projected onto the gear meshing area through a beam splitter. The reflected light signal is received by a photoelectric detector and converted into a gap value. When the monitored value exceeds the preset threshold, the central processing unit triggers the audible and visual alarm module and records the fault timestamp and gap data to the log file.

[0018] Preferably, the atomizing nozzle at the end of the delivery pipe is equipped with a swirl generator inside, the nozzle outlet diameter varies radially with a gradient, and a laser-drilled micron-sized guide hole is provided at the minimum diameter. The axis of the guide hole forms an angle with the axis of the nozzle to enhance the stability of the atomizing cone angle.

[0019] When the atomizing nozzle is working, the swirling generator tangentially introduces the medium into the nozzle cavity, forming a spiral flow. After the medium is accelerated by the radial aperture with a gradient change, it generates jet splitting at the minimum aperture through the micron-level guide hole drilled by laser. The axis of the guide hole is designed to be at an angle with the axis of the nozzle, and the Coanda effect is used to enhance the geometric stability of the atomizing cone angle.

[0020] Preferably, the surface of the cyclone generator is coated with a silicon nitride ceramic coating, and the bonding strength between the silicon nitride ceramic coating and the substrate is verified by ultrasonic non-destructive testing.

[0021] The preparation process of silicon nitride ceramic coating on the surface of cyclone generator is as follows: After the substrate is roughened by sandblasting, the ceramic coating is deposited by plasma spraying technology. The coating thickness is controlled by spraying distance and power parameters. The bonding strength is obtained by scanning the entire cross section with an ultrasonic C-scan detector to generate a three-dimensional bonding strength distribution map.

[0022] Preferably, the non-contact temperature sensor array uses an infrared thermopile sensor, with a sapphire lens on the sensor surface, and the array is installed at an angle to the inner wall of the mixing tank assembly. The field of view coverage of each sensor is spatially calibrated using a blackbody radiation source.

[0023] When installing the non-contact temperature sensor array, the infrared thermopile sensor focuses the thermal radiation signal through a sapphire lens. The sensor array is installed at an angle on the inner wall of the mixing tank assembly. The field of view of each sensor is spatially calibrated by a blackbody radiation source. The calibration data is stored in the controller's FLASH memory. During operation, a lookup table method is used to compensate for the viewing angle deviation.

[0024] In summary, compared with the prior art, the present invention provides a powder additive delivery system with the following beneficial effects: This invention achieves precise proportioning of powder and liquid additives by using a metering feed hopper at the top of the mixing tank assembly in conjunction with a liquid metering injection valve, avoiding operational errors. At the same time, the bottom pneumatic shut-off valve controls the material transfer rhythm through rapid opening and closing, preventing overfilling of the storage tank assembly or accumulation of residue in the mixing tank assembly. The direct connection of the storage tank assembly and the pumping mechanism to the second pipeline design shortens the material transfer path. Combined with the multiple sets of conveying pipes and atomizing nozzles at the pumping mechanism outlet, the system can simultaneously adapt to the spraying station requirements of multiple stenters, significantly improving production efficiency. The dual-shaft differential mechanism of the mixing device forms a three-dimensional shear flow field during the mixing process through the combined action of the inner variable pitch propeller blades and the outer adjustable angle guide plate. The variable pitch structure of the inner blades generates an axial pressure gradient when propelling the material, while the tilt angle dynamic adjustment function of the outer guide plate can change the radial circulation intensity. Combined with the speed difference generated by the independent servo motor drive, the high viscosity powder additives can achieve a more thorough micro-mixing effect, effectively eliminating the stratification and segregation phenomenon that is easy to occur in traditional single-shaft mixing. In the conveying control device, the pulse width modulation control method of the solenoid valve achieves fine adjustment of flow through high-frequency switching. Its self-cleaning flow channel adopts a composite structure of spiral guide groove and ultrasonic vibration component. It automatically removes the adhering material on the pipe wall each time it is closed, avoiding powder crystallization and blockage. The dual turbine flow meter built into the flow regulator forms a redundant measurement mechanism. When the main flow meter detects abnormal fluctuations, the backup flow meter immediately takes over the control to ensure the long-term stability of the spraying volume. The monitoring and feedback module uses a capacitive liquid level sensor to detect the material level in the mixing tank assembly in a non-contact manner. Combined with an infrared spectral concentration sensor for real-time analysis of mixing uniformity, it provides closed-loop control parameters for the central controller. The non-contact temperature sensor array uses infrared thermal imaging technology to monitor the temperature distribution in the mixing area globally. Together with the pressure sensor and vibration monitoring sensor in the storage tank assembly, it forms a multi-dimensional fault early warning mechanism. The dual-redundant CAN bus architecture ensures the anti-interference capability of monitoring data transmission. The adaptive fuzzy PID algorithm module, combined with the feedforward compensation unit, enables the system to respond quickly to interference factors such as raw material viscosity fluctuations and changes in ambient temperature. Attached Figure Description

[0025] Figure 1 This is a schematic block diagram showing the structural connections of the various components of this invention.

[0026] Figure 2 This is a system block diagram of the present invention.

[0027] Explanation of reference numerals in the attached figures: 1. Mixing tank assembly; 2. Pumping mechanism; 3. Storage tank assembly; 4. Delivery pipe; 5. Solenoid valve. Detailed Implementation

[0028] 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.

[0029] Please see Figure 1 and Figure 2 This invention provides a technical solution: a powder additive delivery system, comprising: System main structure: It includes a mixing tank assembly 1, a storage tank assembly 3, a pumping mechanism 2, and a conveying pipe 4; the top of the mixing tank assembly 1 is equipped with a metering feed hopper and a liquid metering injection valve, and the bottom is connected to the storage tank assembly 3 through a first pipe, which is equipped with a pneumatic shut-off valve; the bottom of the storage tank assembly 3 is equipped with a second pipe, the end of which is connected to the inlet of the pumping mechanism 2; the outlet of the pumping mechanism 2 is connected to multiple sets of conveying pipes 4 through a third pipe, and the end of each set of conveying pipes 4 is equipped with an atomizing nozzle that connects to the spraying station of the stenter; Stirring device: The mixing tank assembly 1 includes a dual-shaft differential speed mixing mechanism, comprising an inner and outer mixing shaft mounted coaxially; the inner mixing shaft is provided with variable pitch spiral mixing blades, and the outer mixing shaft is provided with an annular guide plate for adjusting the tilt angle; the speed difference between the two shafts is controlled by independent servo motors. Conveying control device: Each set of delivery pipes 4 is equipped with a solenoid valve 5 and a flow regulator; the solenoid valve 5 adopts pulse width modulation control and has a self-cleaning flow channel inside; the flow regulator has a built-in dual turbine flow meter; Monitoring and Feedback Module: The mixing tank assembly 1 has a capacitive liquid level sensor, an infrared spectral concentration sensor and a non-contact temperature sensor array installed on its inner wall, and a pressure sensor and a vibration monitoring sensor installed in the storage tank assembly 3. The monitoring data is transmitted to the central controller in real time via a dual-redundant CAN bus. The controller has a built-in adaptive fuzzy PID algorithm module and a feedforward compensation unit. Safety protection devices: The pumping mechanism 2 has a three-stage filtration system at its inlet: the first stage is a stainless steel filter, the second stage is a permanent magnet separator, and the third stage is a polytetrafluoroethylene filter. The storage tank assembly 3 is equipped with a dual-redundant structure of a mechanical safety valve and an electronic pressure relief valve at its top.

[0030] Raw material mixing and temporary storage stage: Solid powder additives are added in a preset ratio through the metering hopper at the top of the mixing tank assembly 1, and liquid additives are injected synchronously through the liquid metering injection valve to form an initial mixture. When the dual-shaft differential speed stirring mechanism is started, the inner stirring shaft drives the variable pitch spiral stirring blades to push the material axially at high speed, while the outer stirring shaft rotates in the opposite direction at low speed to drive the annular guide plate with adjustable tilt angle to form a radial shear flow field. The three-dimensional turbulent mixing effect is generated through the speed difference. During the mixing process, a capacitive liquid level sensor monitors the material height in real time, an infrared spectral concentration sensor detects the uniformity of the components, and a non-contact temperature sensor array monitors the temperature distribution. The data is transmitted to the central controller via a dual-redundant CAN bus. After the mixture meets the standard, the pneumatic shut-off valve opens, and the mixed material flows into the storage tank assembly 3 through the first pipe; Stabilized delivery and precise distribution stage: The pressure sensor inside storage tank assembly 3 monitors the static pressure of the material, and the vibration monitoring sensor detects the risk of sedimentation and stratification. The data is fed back to the central controller to trigger the feedforward compensation unit. When pumping mechanism 2 is started, the material enters the pump body through the second pipeline and passes through a three-stage filtration assembly to complete coarse filtration by stainless steel filter screen, impurity removal by permanent magnet iron separator, and fine filtration by polytetrafluoroethylene filter element in sequence. The pumped material is distributed to multiple sets of conveying pipes 4 via the third pipeline. The solenoid valve 5 of each set of conveying pipes 4 adopts pulse width modulation control mode. The flow pulse opening and closing is achieved by adjusting the duty cycle. Combined with the bidirectional metering function of the dual turbine flow meter in the flow regulator, the instantaneous flow is accurately controlled. The material ultimately passes through the atomizing nozzle; Dynamic optimization and security assurance phase: The central controller has a built-in adaptive fuzzy PID algorithm module that adjusts the stirring speed, pumping pressure and solenoid valve opening in real time based on monitoring data to form a closed-loop control. When the pressure inside storage tank assembly 3 is abnormal, the mechanical safety valve and the electronic pressure relief valve work together to release pressure. The solenoid valve 5's self-cleaning flow channel automatically removes crystals through reverse pulse airflow, maintaining long-term operational stability. Through the synergistic effect of the dual-shaft differential stirring mechanism, the variable pitch propeller blades achieve efficient axial conveying, and the adjustable angle guide plate generates radial shearing. Compared with the traditional single-shaft stirrer, the mixing uniformity is improved and the energy consumption is reduced. The monitoring and feedback module transmits data in real time through a dual-redundant CAN bus. Combined with an adaptive fuzzy PID algorithm and a feedforward compensation unit, it shortens the system response delay and improves anti-interference capability. The solenoid valve 5's self-cleaning flow channel, through its reverse pulse design, extends the crystal removal cycle, while the storage tank assembly 3's vibration monitoring sensor provides early warning of deposition stratification risks, reducing equipment downtime for maintenance.

[0031] The solenoid valve 5 uses a three-stage speed curve design for valve core motion control. The opening stage uses a sinusoidal acceleration curve, and the closing stage uses a trapezoidal deceleration curve. The valve seat chamfer transition structure surface is provided with a hard anodized layer, and the thickness of the anodized layer is positively correlated with the nominal pressure of the valve body.

[0032] The solenoid valve 5 uses a three-segment speed curve planning for valve core motion control. The specific implementation steps are as follows: In the opening stage, the drive circuit outputs a control signal according to the preset sinusoidal acceleration curve, and the valve core is accelerated to start uniformly through current closed-loop control; in the intermediate stage, the valve core maintains a uniform speed motion state, and the position sensor provides real-time feedback of valve core displacement data; in the closing stage, the valve core switches to a trapezoidal deceleration curve, and linear deceleration is achieved by dynamically adjusting the slope of the drive voltage until the valve core is fully closed. The surface of the valve seat chamfer transition structure is formed with a hard anodized layer through a micro-arc oxidation process. The thickness of the anodized layer is matched according to the nominal pressure parameter table of the valve body, and pulse current density control technology is used to ensure the uniformity of the film layer. The three-stage speed curve design effectively reduces the impact of valve core opening and closing, extending the service life of the solenoid valve; the sinusoidal acceleration curve can reduce mechanical vibration, and the trapezoidal deceleration curve ensures the smoothness of the closing process; the hard anodized layer significantly improves the surface hardness and wear resistance of the valve seat, and the oxide layer thickness is positively correlated with the nominal pressure, optimizing the sealing reliability under high pressure conditions.

[0033] The automatic calibration module of the infrared spectral concentration sensor is equipped with an ambient light shielding unit. The shielding unit uses a dual-frequency rotating chopper, and the chopping frequency maintains a synchronous phase difference with the light source modulation frequency.

[0034] When the automatic calibration module of the infrared spectral concentration sensor performs ambient light shielding, the dual-frequency rotary chopper operates in synchronous phase difference mode: the main control unit generates a reference pulse signal according to the modulation frequency of the light source, drives the motor to rotate the dual-frequency chopper, and monitors the position of the chopper in real time through the photoelectric encoder, so that the opening period of the light-transmitting window and the flashing period of the light source maintain a certain phase difference, forming a physical shielding effect. The dual-frequency rotary chopper effectively suppresses ambient light interference, and the phase difference synchronization design eliminates the influence of light intensity fluctuations on the detection signal, significantly improving the measurement stability of the concentration sensor under complex lighting conditions.

[0035] The annular guide plate on the surface of the outer stirring shaft of the dual-shaft differential stirring mechanism can be dynamically adjusted in circumferential tilt angle through an electric adjustment mechanism. The adjustment mechanism has a built-in angle encoder and an independent servo motor to form a closed-loop control circuit. A dead zone compensation module is set in the control circuit to eliminate the angle deviation caused by gear backlash.

[0036] The adjustment process of the outer stirring shaft guide plate of the dual-shaft differential stirring mechanism is as follows: The independent servo motor drives the ball screw through the planetary reducer to convert the rotational motion into the circumferential tilting motion of the guide plate. The angle encoder collects the current tilt angle in real time and feeds it back to the PID controller. When the deviation between the actual angle and the set value exceeds the dead zone threshold, the control loop triggers the compensation algorithm to eliminate the angle lag caused by the gear backlash by adjusting the motor pulse duty cycle. The dynamic angle adjustment mechanism optimizes the flow field distribution, the closed-loop control loop ensures the positional accuracy of the guide plate, and the dead zone compensation module effectively offsets mechanical transmission errors, thereby improving mixing efficiency and process repeatability.

[0037] The electric adjustment mechanism adopts a planetary gear reducer and ball screw combined transmission structure, and the ball screw lead is linearly proportional to the adjustment range of the guide plate. The proportional coefficient is calibrated experimentally and stored in the non-volatile memory of the central controller.

[0038] The electric adjustment mechanism adopts a combination of planetary gear reducer and ball screw transmission: the planetary reducer converts the high-speed input of the servo motor into low-speed, high-torque output, and the ball screw converts the rotational motion into linear displacement. The tilt angle of the guide plate is precisely controlled through the linear relationship between the lead of the screw and the displacement of the nut. The central controller calls the corresponding parameters according to the proportional coefficient library calibrated in the experiment to complete the angle-displacement conversion calculation. The combined transmission structure balances high precision and high rigidity. The linear proportional relationship design simplifies the complexity of the control algorithm, and the non-volatile memory ensures the reliability of parameter calls, making it suitable for dynamic adjustment scenarios under multiple working conditions.

[0039] The pumping mechanism 2 adopts a positive displacement gear pump. Pressure balance valves are installed at the pump body inlet and outlet, and the pump shaft seal adopts a double-end mechanical seal structure. The sealing surface is equipped with a spiral groove dynamic pressure lubrication structure, and the lubricating oil circuit and the pumping medium are physically separated by a ceramic isolation sleeve.

[0040] When the positive displacement gear pump is running, the pressure balance valve at the inlet and outlet of the pump body senses the pressure difference through an elastic diaphragm. When the inlet pressure fluctuates, the diaphragm deforms and drives the valve core to open the compensation channel to maintain a constant pressure difference between the inlet and outlet. The double-end mechanical seal adopts a cartridge structure. The sealing end face is supplied with oil by a spiral groove dynamic pressure lubrication system. The lubricating oil forms a physical barrier with the pumping medium through a ceramic isolation sleeve to prevent the medium from penetrating into the bearing area. The pressure balancing valve effectively eliminates pulsating shocks and extends the service life of the gear pump; the double-end sealing structure improves the reliability of high-pressure sealing; the spiral groove dynamic pressure lubrication reduces frictional power consumption; and the ceramic isolation sleeve achieves zero media leakage.

[0041] The gear pairs of the positive displacement gear pump are carburized and quenched. The gear meshing clearance is monitored online by a laser rangefinder. When the clearance exceeds a certain level, an audible and visual alarm device is triggered.

[0042] The online monitoring process for the gear pair of the positive displacement gear pump is as follows: The laser rangefinder emits a red laser of a certain wavelength, which is projected onto the gear meshing area through a beam splitter. The reflected light signal is received by the photoelectric detector and converted into a gap value. When the monitored value exceeds the preset threshold, the central processing unit triggers the audible and visual alarm module and records the fault timestamp and gap data to the log file. Laser ranging technology enables non-contact gap monitoring, carburizing and quenching treatment improves the surface hardness of gears, and an audible and visual alarm system provides timely warnings of abnormal operating conditions, ensuring the safety of equipment operation.

[0043] The atomizing nozzle at the end of the delivery pipe 4 is equipped with a swirling generator. The nozzle outlet orifice diameter varies radially with a gradient. A laser-drilled micron-sized guide hole is provided at the minimum orifice diameter. The axis of the guide hole forms an angle with the nozzle axis to enhance the stability of the atomizing cone angle.

[0044] When the atomizing nozzle is working, the swirling generator tangentially introduces the medium into the nozzle cavity to form a spiral flow. After the medium is accelerated by the radial aperture with a gradient change, it generates jet splitting at the minimum aperture through the micron-level guide hole drilled by laser. The axis of the guide hole is designed to be at an angle with the axis of the nozzle, and the Coanda effect is used to enhance the geometric stability of the atomizing cone angle. The swirl generator improves the uniformity of atomized particle size, the gradient aperture design optimizes the flow field distribution, the micron-level guide holes improve atomization efficiency, and the axial angle design significantly enhances the spatial stability of the atomization field.

[0045] A silicon nitride ceramic coating is applied to the surface of the cyclone generator, and the bonding strength between the silicon nitride ceramic coating and the substrate is verified by ultrasonic non-destructive testing.

[0046] The preparation process of silicon nitride ceramic coating on the surface of cyclone generator is as follows: After the substrate is roughened by sandblasting, the ceramic coating is deposited by plasma spraying technology. The coating thickness is controlled by spraying distance and power parameters. The bonding strength is obtained by scanning the entire cross section with an ultrasonic C-scan detector to generate a three-dimensional bonding strength distribution map. Silicon nitride ceramic coating significantly improves the erosion resistance of cyclone generators, and ultrasonic non-destructive testing ensures controllable coating quality and extends nozzle maintenance cycles.

[0047] The non-contact temperature sensor array uses an infrared thermopile sensor with a sapphire lens on the sensor surface. The array is installed at an angle to the inner wall of the mixing tank assembly 1. The field of view coverage of each sensor is spatially calibrated using a blackbody radiation source.

[0048] When the non-contact temperature sensor array is installed, the infrared thermopile sensor focuses the thermal radiation signal through the sapphire lens. The sensor array is installed at an angle on the inner wall of the stirring tank assembly 1. The field of view of each sensor is spatially calibrated by a blackbody radiation source. The calibration data is stored in the controller's FLASH memory. During operation, the lookup table method is used to compensate for the viewing angle deviation. Sapphire lenses improve infrared transmittance, array angle mounting expands monitoring coverage, and blackbody calibration eliminates installation errors.

[0049] This solution involves installing the mixing tank assembly 1 on a foundation platform, fixing a metering feed hopper and a liquid metering injection valve at the top, and connecting the bottom to the storage tank assembly 3 via a first pipe, with a pneumatic shut-off valve installed on the first pipe. Storage tank assembly 3 is positioned below mixing tank assembly 1, with a second pipe connected to its bottom and the end of the second pipe connected to the inlet of pumping mechanism 2. The outlet of the pumping mechanism 2 is connected to a third pipe, which is branched into multiple sets of conveying pipes 4. Each set of conveying pipes 4 is equipped with an atomizing nozzle at its end. A solenoid valve 5 and a flow regulator are configured at the branch node of the delivery pipe 4. The solenoid valve 5 has a self-cleaning flow channel machined inside, and the flow regulator has a dual turbine flow meter embedded in it. An inner stirring shaft and an outer stirring shaft are coaxially installed inside the stirring tank assembly 1. The surface of the inner stirring shaft is machined with variable pitch spiral stirring blades. An annular guide plate with adjustable tilt angle is arranged on the surface of the outer stirring shaft. The guide plate is connected to an independent servo motor through an electric adjustment mechanism. A dual-axis speed difference control system is established, in which the inner stirring shaft is driven by a high-speed servo motor, and the outer stirring shaft is driven in reverse by a low-speed servo motor. A capacitive liquid level sensor, an infrared spectral concentration sensor, and a non-contact temperature sensor array are arranged in a ring array on the inner wall of the mixing tank assembly 1. The storage bucket assembly 3 is equipped with a pressure sensor and a vibration monitoring sensor, and the sensor signal lines are connected to a dual redundant CAN bus interface. The central controller integrates an adaptive fuzzy PID algorithm module and a feedforward compensation unit, and receives sensor data and outputs control commands via the CAN bus. A three-stage filtration assembly consisting of a stainless steel filter screen, a permanent magnet iron remover, and a polytetrafluoroethylene filter element is installed sequentially at the inlet of the pumping mechanism 2. The top of the storage tank assembly 3 is equipped with a mechanical safety valve and an electronic pressure relief valve, and the dual valve pressure relief channels are independently set and connected in parallel to the waste liquid collection system.

[0050] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A powder additive delivery system, characterized in that, include: System main structure: The system includes a mixing tank assembly (1), a storage tank assembly (3), a pumping mechanism (2), and a conveying pipe (4). The mixing tank assembly (1) is equipped with a metering feed hopper and a liquid metering injection valve at the top, and is connected to the storage tank assembly (3) at the bottom through a first pipe. The first pipe is equipped with a pneumatic shut-off valve. The storage tank assembly (3) is equipped with a second pipe at the bottom, and the end of the second pipe is connected to the inlet of the pumping mechanism (2). The outlet of the pumping mechanism (2) is connected to multiple sets of conveying pipes (4) through a third pipe. Each set of conveying pipes (4) is equipped with an atomizing nozzle at the end that is connected to the spraying station of the stenter. Stirring device: The mixing tank assembly (1) includes a dual-shaft differential stirring mechanism, which includes an inner stirring shaft and an outer stirring shaft mounted coaxially; the surface of the inner stirring shaft is provided with a variable pitch spiral stirring blade, and the surface of the outer stirring shaft is provided with an annular guide plate for adjusting the tilt angle; the speed difference between the two shafts is controlled by an independent servo motor. Conveying control device: Each set of delivery pipes (4) is equipped with a solenoid valve (5) and a flow regulator; the solenoid valve (5) adopts pulse width modulation control mode and is equipped with a self-cleaning flow channel; the flow regulator has a built-in dual turbine flow meter; Monitoring and Feedback Module: The mixing tank assembly (1) has a capacitive liquid level sensor, an infrared spectral concentration sensor and a non-contact temperature sensor array installed on its inner wall, and a pressure sensor and a vibration monitoring sensor installed in the storage tank assembly (3). The monitoring data is transmitted to the central controller in real time via a dual redundant CAN bus. The controller has an adaptive fuzzy PID algorithm module and a feedforward compensation unit built in. Safety protection devices: The pumping mechanism (2) has a three-stage filtration system at the inlet, with the first stage being a stainless steel filter, the second stage being a permanent magnet separator, and the third stage being a polytetrafluoroethylene filter element; the storage tank assembly (3) has a dual-redundant structure of a mechanical safety valve and an electronic pressure relief valve at the top.

2. The powder additive conveying system according to claim 1, characterized in that: The solenoid valve (5) uses a three-segment speed curve for valve core motion control. The opening stage uses a sinusoidal acceleration curve, and the closing stage uses a trapezoidal deceleration curve. The valve seat chamfer transition structure surface is provided with a hard anodized layer, and the thickness of the anodized layer is positively correlated with the nominal pressure of the valve body.

3. The powder additive conveying system according to claim 1, characterized in that: The automatic calibration module of the infrared spectral concentration sensor is equipped with an ambient light shielding unit. The shielding unit uses a dual-frequency rotating chopper, and the chopping frequency maintains a synchronous phase difference with the light source modulation frequency.

4. The powder additive conveying system according to claim 1, characterized in that: The annular guide plate on the outer stirring shaft surface of the dual-shaft differential stirring mechanism is dynamically adjusted in circumferential tilt angle through an electric adjustment mechanism. The adjustment mechanism has a built-in angle encoder and an independent servo motor to form a closed-loop control circuit. A dead zone compensation module is set in the control circuit to eliminate the angle deviation caused by gear backlash.

5. A powder additive conveying system according to claim 4, characterized in that: The electric adjustment mechanism adopts a planetary gear reducer and ball screw combined transmission structure, and the ball screw lead is linearly proportional to the adjustment range of the guide plate. The proportional coefficient is experimentally calibrated and stored in the non-volatile memory of the central controller.

6. A powder additive conveying system according to claim 1, characterized in that: The pumping mechanism (2) adopts a positive displacement gear pump, and pressure balance valves are set at the pump body inlet and outlet. The pump shaft seal adopts a double-end mechanical seal structure, and the sealing surface is set with a spiral groove dynamic pressure lubrication structure. The lubricating oil circuit and the pumping medium are physically separated by a ceramic isolation sleeve.

7. A powder additive conveying system according to claim 6, characterized in that: The gear pair of the positive displacement gear pump is carburized and quenched. The gear meshing clearance is monitored online by a laser rangefinder. When the clearance exceeds a certain level, an audible and visual alarm device is triggered.

8. A powder additive conveying system according to claim 1, characterized in that: The atomizing nozzle at the end of the delivery pipe (4) is equipped with a swirling generator. The nozzle outlet diameter varies radially with a gradient. A laser-drilled micron-sized guide hole is provided at the minimum diameter. The axis of the guide hole forms an angle with the axis of the nozzle to enhance the stability of the atomizing cone angle.

9. A powder additive conveying system according to claim 8, characterized in that: The surface of the cyclone generator is coated with a silicon nitride ceramic coating, and the bonding strength between the silicon nitride ceramic coating and the substrate is verified by ultrasonic non-destructive testing.

10. A powder additive conveying system according to claim 1, characterized in that: The non-contact temperature sensor array uses an infrared thermopile sensor, with a sapphire lens on the sensor surface. The array is installed at an angle to the inner wall of the mixing tank assembly (1), and the field of view coverage of each sensor is spatially calibrated by a blackbody radiation source.

Images