Production and blending reaction kettle for suspending agent

Abstract

The invention belongs to the technical field of chemical reaction kettles, and particularly relates to a suspending agent production and blending reaction kettle which comprises a kettle body, a stirring system, a driving device and a control system, and is characterized in that a set of multipoint buoyancy online monitoring system is integrated; the system comprises at least three buoyancy measuring units which are distributed at different key positions (such as a near stirring shaft area, a near kettle wall area and a kettle bottom area) in a kettle, each buoyancy measuring unit is composed of a floater and a displacement sensor, a control system collects signals of all points in real time, the dispersion reflecting the material space uniformity is calculated, and the material space uniformity is obtained. And when the dispersion is lower than a threshold value I in continuous time and the average value of all the measurement points approaches to a preset target value (threshold value II), automatically judging that the allocation is completed and outputting a signal. According to the method, objectification, quantification and automation of judgment of the blending end point of the suspending agent are realized, subjective observation depending on artificial experience is replaced, and the product quality consistency and the production intelligent level are remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chemical reaction kettles, in particular to a suspension agent production and blending reaction kettle. BACKGROUND

[0002] Suspension agent is a solid-liquid dispersion system formed by uniformly dispersing and stably suspending solid particles that are insoluble in liquid medium in the liquid medium through the aid of an auxiliary agent and mechanical action. The core process in its production process is blending, that is, through stirring, shearing, grinding and other operations, the solid particles are made to reach micron-level fineness and are uniformly dispersed to form a stable and uniform suspension.

[0003] At present, the suspension agent production and blending reaction kettle generally relies on the operator to observe the flow state, color uniformity and other apparent characteristics of the material in the kettle through the sight window and to judge whether the blending is completed by experience. This method has the following significant drawbacks: 1) Strong subjectivity: the experience difference of different operators leads to different judgment standards, resulting in large fluctuations in product quality; 2) Poor accuracy: apparent uniformity does not mean microscopic uniform dispersion, which can easily lead to excessive stirring or insufficient stirring; 3) Cannot be quantified and traced: the judgment process lacks objective data support, which is not conducive to process optimization and quality tracing; 4) Low degree of automation: it is difficult to realize closed-loop automatic control of the production process.

[0004] Therefore, there is an urgent need for a technical solution that can monitor the uniformity of the material in the kettle in real time, objectively and quantitatively, and automatically and accurately determine the blending endpoint, so as to improve the standardization, intelligentization and product quality consistency of suspension agent production. SUMMARY

[0005] Based on the technical problems existing in the prior art, the present application provides a suspension agent production and blending reaction kettle.

[0006] The suspension agent production and blending reaction kettle provided by the present application comprises a kettle body, a stirring system, a driving device and a control system, and further comprises: at least three buoyancy measuring units, which are distributedly arranged at different positions in the internal space of the kettle body; each buoyancy measuring unit comprises a float suspended in the material and a displacement sensor for measuring the vertical displacement of the float; The control system is connected with all the displacement sensors and is configured to receive the signals of the displacement sensors and calculate the dispersion degree representing the spatial uniformity of the material in the kettle based on the measurement data of all the buoyancy measuring units; when the dispersion degree meets a first preset condition and the average value of all the measurement data meets a second preset condition, it is determined that the blending is completed.

[0007] Preferably, the float is a sealed hollow structure, and the outer surface of the float is covered with an anti-adhesion coating.

[0008] Preferably, the shape of the float is streamlined or spherical.

[0009] Preferably, the displacement sensor is a magnetostrictive displacement sensor, and a waveguide tube of the displacement sensor is vertically and sealingly installed on the top of the kettle body, and a magnetic ring is fixed in the interior or upper portion of the float and is in contactless coupling with the waveguide tube.

[0010] Preferably, the waveguide tube is packaged in a vertically arranged sealed protection tube, and the sealed protection tube is sealingly connected with the top of the kettle body through a mounting flange.

[0011] Preferably, the number of the buoyancy measuring units is three, including a first buoyancy measuring unit, a second buoyancy measuring unit and a third buoyancy measuring unit; the first buoyancy measuring unit is located in a middle upper region close to the stirring shaft, the second buoyancy measuring unit is located in a middle lower region close to the inner wall of the kettle body, and the third buoyancy measuring unit is located in a central region of the kettle bottom.

[0012] Preferably, the control system comprises a signal processing module and an algorithm judgment module. The signal processing module is used for filtering and moving average processing of the signals of the displacement sensors to obtain stable measurement values of the measuring points. The algorithm judgment module is used for calculating the dispersion D and the average value M_avg of all the stable measurement values and executing a judgment logic.

[0013] Preferably, the first preset condition is that the dispersion D is less than a first preset threshold ε1 in a continuous first time period T1. The second preset condition is that the absolute value of the difference between the average value M_avg and a preset target value M_target is less than a second preset threshold ε2 in a continuous second time period T2.

[0014] Preferably, the control system is further connected with a man-machine interface for displaying real-time data, historical curves and deployment states of the buoyancy measuring units and receiving parameter setting instructions.

[0015] Preferably, the control system is configured to output a control instruction to stop the driving device or trigger a subsequent process after determining that the deployment is completed.

[0016] Compared with the prior art, the present application provides a suspension agent production deployment reaction kettle, which has the following beneficial effects: Objective and quantitative judgment: through multi-point buoyancy measurement, the spatial uniformity of the material is directly converted into quantifiable data, completely replacing subjective experience judgment, and ensuring stable product quality.

[0017] Comprehensive and accurate monitoring: Monitoring points are set up in key locations inside the vessel (such as areas prone to settling and dead corners) to accurately reflect the overall mixing state and avoid misjudgments caused by local unevenness.

[0018] The endpoint determination is accurate and reliable: the dual criteria of spatial consistency and target value compliance are adopted to ensure that the determination of the completion of the blending reflects both the uniform process and meets the final product quality requirements.

[0019] Achieving automation and intelligence: It provides core data input and decision-making basis for the automatic shutdown of the reactor, the automatic triggering of the next process, and the optimization of production process parameters.

[0020] Simple structure and easy to modify: The sensing unit has a reliable structure and is easy to install and modify on existing reactors, with low implementation cost. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the present invention; Figure 3 This is a schematic diagram of the buoyancy measurement unit structure of the present invention; Figure 4 This is a flowchart illustrating the logic decision-making process of the control system of the present invention.

[0022] In the diagram: 1. Vessel body; 101. Jacket; 2. Stirring system; 201. Stirring shaft; 202. Stirring blade; 3. Drive unit; 4. Feed inlet; 5. Discharge outlet; 6. Viewing window; 7. Control system; 701. Human-machine interface; 8. Buoyancy measurement unit; 801. First buoyancy measurement unit; 802. Second buoyancy measurement unit; 803. Third buoyancy measurement unit; 81. Float; 811. Magnetic ring; 82. Displacement sensor; 821. Waveguide; 822. Sensor head; 83. Mounting flange; 84. Sealing protection tube. Detailed Implementation

[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0024] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0025] Please see Figure 1 The present invention provides a suspension preparation reactor, which mainly includes a reactor body 1, a stirring system 2, a driving device 3, and a control system 7.

[0026] The vessel body 1 is a vertical cylindrical pressure vessel. The top of the vessel body 1 is provided with a feed port 4 and the bottom is provided with a discharge port 5. A viewing window 6 for manual observation can be provided on the side wall. The viewing window 6 is made of high-strength borosilicate glass and is embedded in the flange seat of the head or the side wall of the vessel body. The glass and the flange seat are sealed by a fluororubber sealing ring, which facilitates the operator to conduct auxiliary observation during the production process without affecting the sealing performance of the vessel body.

[0027] The vessel body 1 may be equipped with a jacket 101 for heating or cooling. The jacket 101 and the outer wall of the vessel body 1 form a sealed chamber for introducing a heating medium (such as steam or heat transfer oil) or a cooling medium (such as cooling water or refrigerant) to achieve precise temperature control of the material inside the vessel (temperature control accuracy can reach ±1℃). The jacket 101 is equipped with a medium inlet, outlet, vent, and drain outlet to ensure that the medium can fill the entire jacket chamber and achieve uniform heat transfer. The vent outlet is used to discharge non-condensable gases in the chamber to avoid the formation of heat transfer dead zones. The drain outlet is used to periodically clean the impurities and scale deposits inside the jacket to ensure long-term heat transfer performance.

[0028] The mixing system 2 includes a stirring shaft 201 extending vertically into the vessel body 1 and multi-layered stirring blades 202 mounted on the stirring shaft 201. The upper blades are propeller-type blades, similar in shape to propellers, which have strong axial conveying capacity and can push the material in the upper part of the vessel body downwards, promoting the circulation and mixing of the upper and lower layers of material. The lower blades are anchor-type or ribbon-type blades, close to the bottom and side walls of the vessel body, which can effectively stir the material in the easily settling areas, prevent solid particles from depositing at the bottom of the vessel body, and eliminate mixing dead zones. The drive unit 3 is usually composed of a motor, a reducer, a coupling, and a mounting base. It is mounted on the motor bracket at the top of the vessel body 1 and fixed to the vessel head with bolts to ensure stability during operation. It drives the stirring shaft 201 to rotate to achieve mixing, dispersion, and shearing of the material.

[0029] The core improvement of this invention lies in the integration of a multi-point buoyancy online monitoring system, which is used to determine the allocation endpoint in real time and objectively. The system mainly consists of multiple distributed buoyancy measurement units 8 and a control system 7 with a specific algorithm.

[0030] I. Composition and Installation Method of Buoyancy Measurement Unit 8 Please combine Figure 2 and Figure 3In this embodiment, three buoyancy measurement units 8 are provided, which are respectively labeled as the first buoyancy measurement unit 801, the second buoyancy measurement unit 802 and the third buoyancy measurement unit 803. The three buoyancy measurement units 8 have completely identical structures, each consisting of a float 81, a displacement sensor 82, a sealing protection tube 84 and a mounting flange 83. Their design and installation fully consider the sealing requirements, measurement accuracy and service life of the reactor.

[0031] Float 81: Float 81 is the core component that senses changes in the buoyancy of the material. Its design must meet the following requirements: its density must be within the density range of the final product of the suspending agent to be prepared, so as to ensure that it can be suspended in the material; its shape should be conducive to reducing fluid resistance and preventing material adhesion; and its structure must be sealed and corrosion resistant.

[0032] In this embodiment, the float 81 is designed as a streamlined, rotating (bullet-shaped) sealed hollow structure, made of 316L stainless steel, with its outer surface entirely coated with a polytetrafluoroethylene (PTFE) anti-adhesion coating. This shape and coating effectively reduce particle deposition and adhesion on the surface of the float 81, ensuring its sensitivity to density changes. A magnetic ring 811 made of permanent magnet material is fixedly installed in the internal cavity of the float 81.

[0033] Displacement sensor 82: The displacement sensor 82 is used to measure the vertical displacement of the float 81 with high precision. In this embodiment, a non-contact magnetostrictive displacement sensor is preferably used due to its advantages of high precision, long lifespan, high pressure resistance, and good reliability. The displacement sensor 82 mainly includes a waveguide 821 and a sensor head 822. Its installation method is as follows: The waveguide 821 is a slender metal tube that serves as a sensing element. It is encapsulated inside a vertical, sealed protective tube 84. The sealed protective tube 84 is made of a material compatible with the vessel body 1 (such as 316L stainless steel). Its lower end is open or equipped with a protective filter to allow material to enter. Its upper end is sealed to the top cover or upper end cap of the vessel body 1 via a mounting flange 83 (such as by using quick-release clamps or bolts). This installation method ensures the pressure seal integrity of the reactor.

[0034] The upper end of the waveguide 821 is connected to the sensor head 822, which is fixed above the mounting flange 83 and contains electronic components for transmitting interrogation pulses and receiving return signals.

[0035] The float 81 is constrained outside the sealed protective tube 84 by its connecting rod or its own structure, so that it can only float freely along the axial direction (i.e., vertical direction) of the sealed protective tube 84. The magnetic ring 811 inside the float 81 forms a non-contact magnetic coupling with the waveguide 821 inside the sealed protective tube 84.

[0036] Measurement Principle and Signal Output: During operation, the sensor head 822 emits an electrical pulse along the waveguide 821. When this pulse encounters the magnetic field of the magnetic ring 811 inside the float 81, a returning strain pulse is generated. By measuring the time difference between the emission of the electrical pulse and the return of the strain pulse, the absolute position (displacement) of the magnetic ring 811 (i.e., the float 81) relative to the sensor head 822 can be accurately calculated. When the equivalent density of the material at the location of the float 81 (related to the concentration and dispersion of solid particles) changes, the buoyancy acting on the float 81 changes accordingly, causing the suspension position of the float 81 to shift vertically. The displacement sensor 82 transmits this displacement (e.g., a 4-20mA current signal or a digital communication signal) to the control system 7 in real time.

[0037] The placement strategy of the buoyancy measurement units 8: The placement of the three buoyancy measurement units 8 (first buoyancy measurement unit 801, second buoyancy measurement unit 802, and third buoyancy measurement unit 803) is crucial for accurately assessing the overall uniformity. The placement design in this embodiment is as follows: The first buoyancy measuring unit 801 is installed in the upper-middle region near the stirring shaft 201 (located at 1 / 3 of the vessel's height from the top, and 50-100mm from the stirring shaft). This region is at the core of the flow field of the main mixing body. The rotation of the stirring blades 202 drives the material to form strong axial and radial flows, resulting in optimal mixing and typically the highest material uniformity. The measurement data from this unit serves as a "reference area," reflecting the ideal state of material mixing and providing a benchmark for comparison with measurement data from other regions.

[0038] The second buoyancy measuring unit 802 is installed in the lower-middle region near the inner wall of the vessel body 1 (one-third of the vessel's height from the bottom, 50-100mm from the vessel wall). This region is far from the stirring shaft, resulting in weaker stirring intensity and slower material flow (approximately one-fifth to one-third of the core region). It is a "wall area" where solid particles are prone to settling or accumulating. Due to the viscosity of the vessel wall, the flow boundary layer near the wall is relatively thick (approximately 5-10mm), leading to low mixing efficiency and a tendency for localized unevenness. Installing the measuring unit at this location effectively monitors the mixing state in the wall area, preventing product quality issues caused by uneven mixing in the wall area compared to a uniform core area.

[0039] The third buoyancy measuring unit 803 is installed in the central area of ​​the reactor bottom (20-50mm from the bottom of the reactor body). This area is the most typical mixing "dead zone" in the reactor, which is difficult to completely cover by the stirring blades 202. The material flow is extremely slow (about 1 / 10-1 / 5 of the core area), and solid particles are most likely to settle, especially in the later stages of suspension production. When the material viscosity increases, the risk of particle deposition in the reactor bottom area is even higher. Setting the measuring unit at this location can most sensitively capture changes in the overall mixing uniformity. If the material in this area can reach a uniform state, it can be considered that the material in the entire reactor has been mixed uniformly.

[0040] The three measuring units are evenly distributed along the circumference, with the center angle between any two adjacent measuring units being 120°, ensuring the uniformity of the measuring points in the radial direction. Simultaneously, the lengths of the waveguides 821 of the three measuring units are precisely matched to their placement height, ensuring that the float 81 is always within the effective mixing zone of the material, avoiding measurement data distortion due to the float 81 being too high or too low.

[0041] II. Control Logic of Control System 7 Please see Figure 1 , Figure 2 , Figure 3 and Figure 4 The control system 7 can be a functional module of an independent industrial computer, PLC (Programmable Logic Controller), or DCS (Distributed Control System). Its hardware includes a signal acquisition card, processor, memory, and human-machine interface 701. In terms of software, it is programmed to execute the following core control logic: Step S1: Signal acquisition and preprocessing.

[0042] The signal processing module of control system 7 synchronously acquires displacement signals L1(t), L2(t), and L3(t) from the first buoyancy measurement unit 801, the second buoyancy measurement unit 802, and the third buoyancy measurement unit 803 in real time via an analog input module or communication interface. Since turbulence during stirring causes high-frequency micro-amplitude fluctuations in the float 81, the original signal contains noise. Therefore, the signal from each channel is first subjected to software low-pass filtering (e.g., using a first-order low-pass digital filter) to remove high-frequency noise. Then, the filtered signal is processed by moving average (e.g., taking the average of the data from the most recent 10 seconds) to obtain the relatively stable displacement values ​​S1, S2, and S3 of each measurement point at the current moment. This step aims to extract stable trend values ​​reflecting the macroscopic density state of the material from the dynamic process.

[0043] Step S2: Physical quantity conversion and characteristic value calculation.

[0044] Based on the geometric parameters and mass of float 81, the stable displacement value S_i (i=1,2,3) can be converted into the equivalent density value ρ_i of the material at that point using a pre-calibrated curve, or the relative buoyancy value F_i (usually normalized to 0-100% or engineering units) after zero-point and range calibration can be used directly. For simplicity, the term "measured value M_i" will be used below to represent the processed valid data.

[0045] Calculate the average value M_avg of all measurement points at the current time: M_avg = (M1 + M2 + M3) / 3; The dispersion D, which reflects the spatial uniformity, can be calculated. The dispersion D can be represented by the standard deviation or the range (the difference between the maximum and minimum values). In this embodiment, the range is used as an example: D=max(M1,M2,M3)-min(M1,M2,M3).

[0046] Step S3: Determine the endpoint of the adjustment (dual criteria).

[0047] The algorithm judgment module of control system 7 continuously performs the following judgments: Spatial consistency criterion (uniformity criterion): This criterion determines whether the dispersion D has reached a stable and sufficiently small state. Specifically, within a continuous first time period T1 (e.g., 30 seconds), the dispersion D is consistently less than a first preset threshold ε1 (e.g., corresponding to a density difference of 0.5% or a relative buoyancy value of 1%). This criterion ensures that the material properties at various locations within the vessel are very similar.

[0048] Target compliance criterion (endpoint criterion): Determines whether the overall material state has met the final target of the process requirements. Specifically, within a continuous second time period T2 (e.g., 20 seconds), the absolute value of the difference between the average value M_avg and the preset "target value M_target" is consistently less than a second preset threshold ε2. The target value M_target is determined through previous production tests and corresponds to the stable value that the buoyancy measurement unit 8 should achieve when the product formulation is perfectly completed. This value can be stored in the formula database of the control system for different formulas.

[0049] Step S4: Output the endpoint signal and execute the action.

[0050] The algorithm judgment module determines that the current suspension preparation process is complete if and only if the spatial consistency criterion and the target conformity criterion in step S3 are satisfied simultaneously.

[0051] Subsequently, control system 7 immediately performs the following operations: The "Dispensing Complete" status is highlighted on the human-machine interface 701, and an audio-visual prompt is issued.

[0052] Send a command to the drive unit 3 of the reactor to stop stirring (or switch to low-speed maintenance mode).

[0053] Optionally, a process completion signal can be sent to the upper-level production management system (MES) via a communication interface, or a chain action such as starting the discharge pump and feeding the next batch can be automatically triggered.

[0054] All data from this allocation process (displacement curves, dispersion curves, judgment time points, etc.) will be stored and recorded for quality traceability and production report generation.

[0055] III. System Calibration and Learning Functions To ensure long-term accuracy, this system incorporates a calibration function. For mature formulations, operators can initiate the "calibration" mode on control system 7 after confirming that a batch of products has passed inspection. The system will automatically record the final data at each measurement point under the current stable state and calculate its average value as the new target value M_target for the formulation, storing it in the database. Simultaneously, the system can automatically suggest or update thresholds ε1 and ε2 based on data fluctuations during a stable period. This function enables the system to possess a certain degree of self-learning and process adaptation capabilities.

[0056] In summary, by arranging multiple buoyancy measurement units 8 at key locations within the reactor and employing specially designed control logic, this invention achieves objective, accurate, and automatic judgment of the endpoint of suspendant preparation. This not only significantly improves the consistency of product quality but also lays a solid foundation for the digital and intelligent upgrading of the production process.

[0057] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A suspension preparation reactor, comprising a reactor body (1), a stirring system (2), a driving device (3), and a control system (7), characterized in that, Also includes: At least three buoyancy measuring units (8) are distributed in different positions inside the vessel body (1); each buoyancy measuring unit (8) includes a float (81) suspended in the material and a displacement sensor (82) for measuring the vertical displacement of the float (81). The control system (7) is connected to all the displacement sensors (82) and is configured to: receive the signals of each displacement sensor (82) and calculate the dispersion of the uniformity of the material space in the vessel based on the measurement data of all buoyancy measurement units (8); when the dispersion meets the first preset condition and the average value of all measurement data meets the second preset condition, the mixing is determined to be completed.

2. The suspension preparation reactor according to claim 1, characterized in that, The float (81) is a sealed hollow structure with an anti-adhesion coating on its outer surface.

3. The suspension preparation reactor according to claim 2, characterized in that, The float (81) is streamlined or spherical in shape.

4. The suspension preparation reactor according to claim 1, characterized in that, The displacement sensor (82) is a magnetostrictive displacement sensor. The waveguide (821) of the displacement sensor (82) is vertically and sealed on the top of the vessel body (1). The float (81) has a magnetic ring (811) that is not in contact with the waveguide (821) fixed inside or on the top.

5. The suspension preparation reactor according to claim 4, characterized in that, The waveguide (821) is encapsulated in a vertically arranged sealed protective tube (84), which is sealed to the top of the vessel body (1) via a mounting flange (83).

6. The suspension preparation reactor according to claim 1, characterized in that, The number of buoyancy measuring units (8) is three, including a first buoyancy measuring unit (801), a second buoyancy measuring unit (802) and a third buoyancy measuring unit (803); the first buoyancy measuring unit (801) is located in the upper middle region near the stirring shaft (201), the second buoyancy measuring unit (802) is located in the lower middle region near the inner wall of the vessel body (1), and the third buoyancy measuring unit (803) is located in the center region of the bottom of the vessel.

7. The suspension preparation reactor according to claim 1, characterized in that, The control system (7) includes a signal processing module and an algorithm judgment module; The signal processing module is used to filter and perform moving average processing on the signals of each displacement sensor (82) to obtain stable measurement values ​​at each measurement point; The algorithm judgment module is used to calculate the dispersion D and average value M_avg of all stable measurements and execute the judgment logic.

8. The suspension preparation reactor according to claim 7, characterized in that, The first preset condition is: the dispersion D is less than the first preset threshold ε1 within a continuous first time period T1; The second preset condition is: the absolute value of the difference between the average value M_avg and the preset target value M_target within a continuous second time period T2 is less than the second preset threshold ε2.

9. The suspension preparation reactor according to claim 1, characterized in that, The control system (7) is also connected to a human-machine interface (701) to display the real-time data, historical curves and adjustment status of each buoyancy measurement unit (8) and to receive parameter setting instructions.

10. A suspension preparation reactor according to any one of claims 1-9, characterized in that, The control system (7) is configured to output a control command to stop the drive device (3) or trigger a subsequent process after the determination and adjustment are completed.

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