A reaction kettle for magnesium sulfate production

Abstract

This invention belongs to the field of reaction vessel technology, specifically a reaction vessel for magnesium sulfate production. It includes a vessel body, a vessel cover, a feed pipe, a discharge pipe, a stirring assembly, and a wall scraping assembly. The wall scraping assembly includes a translation unit, a scraper fixing frame, a mounting base, a scraper, and a pressure detection unit. The translation unit is fixed to the stirring rod of the stirring assembly via the mounting base, and its output shaft is connected to the scraper fixing frame. The scraper is embedded in the slot of the scraper fixing frame. The pressure detection unit is located at the connection between the translation unit and the scraper fixing frame. Before stirring, the translation unit drives the scraper close to the inner wall of the vessel. During stirring, the pressure detection unit detects the pressure in real time, and the controller calculates the instantaneous pressure change coefficient. If the coefficient exceeds a threshold, the translation unit retracts, moving the scraper away from the inner wall, and then gradually moves it closer again. This avoids strong collisions between the scraper and the material on the inner wall, preventing damage and improving the stability and service life of the equipment.

Description

Technical Field

[0001] This invention relates to the field of reaction vessel technology, and more particularly to a reaction vessel for the production of magnesium sulfate. Background Technology

[0002] In the production of magnesium sulfate, the reaction vessel is one of the core pieces of equipment. The preparation of magnesium sulfate typically involves neutralization or crystallization processes, requiring thorough mixing and stirring of the reactants within the vessel to ensure uniform reaction and improve product purity. However, during stirring, the reactants easily form scale or deposits on the inner wall of the vessel. These deposits not only affect heat transfer efficiency but may also lead to incomplete localized reactions, reducing product quality.

[0003] Existing reactors are typically equipped with wall scraping devices to remove adhering materials from the inner wall. However, traditional scraping devices mostly use fixed scraper blades, maintaining a constant gap or continuous contact with the inner wall. During stirring, if the material has high viscosity or contains granular solids, the scraper blades are prone to violent collisions with the inner wall due to the obstruction of material particles, leading to scraper blade wear or even damage, and potentially damaging the inner wall of the reactor. Furthermore, continuous high-pressure contact increases the load on the stirring components, affecting the long-term stability and service life of the equipment. Therefore, effectively preventing scraper blades from being damaged by violent collisions with materials on the inner wall during stirring has become a pressing technical problem to be solved in this field. Summary of the Invention

[0004] Based on the technical problems existing in the prior art, the present invention proposes a reaction vessel for the production of magnesium sulfate.

[0005] This invention proposes a reaction vessel for magnesium sulfate production, comprising a vessel body, a vessel cover, a feed pipe, a discharge pipe, a stirring assembly, and at least one wall scraping assembly. The wall scraping assembly includes a translation unit, a scraper fixing frame, a mounting base, a scraper, and a pressure detection unit. The translation unit is fixed to the stirring rod of the stirring assembly via the mounting base. The output shaft of the translation unit is fixedly connected to the scraper fixing frame. The scraper is embedded in the slot of the scraper fixing frame and fixed with bolts. The pressure detection unit is installed at the connection between the translation unit and the scraper fixing frame.

[0006] Preferably, the translation unit is a linear module or a linear actuator.

[0007] Preferably, the output shaft of the translation unit is fixedly connected to the scraper fixing frame through a fixing sleeve, and the fixing sleeve has a mounting groove on the side near the scraper fixing frame, and the pressure detection unit is embedded in the mounting groove.

[0008] Preferably, the pressure detection unit is a thin-film pressure sensor.

[0009] Preferably, the scraper fixing frame is further fixed with a plurality of guide posts, the other ends of which pass through the corresponding round holes on the stirring rod.

[0010] Preferably, the stirring assembly includes a central shaft, multiple stirring rod mounting brackets, multiple stirring rods, and a motor; the central shaft is vertically mounted downwards at the center of the vessel lid, the multiple stirring rod mounting brackets are evenly distributed and fixedly mounted on the central shaft, and the multiple stirring rods are mounted in a circumferential array on each stirring rod mounting bracket; the motor is fixed to the top of the vessel lid, and the output shaft of the motor is connected to the end of the central shaft via a coupling.

[0011] Preferably, the outer periphery of the vessel body is further provided with an insulation layer integrally formed with the vessel body, and a heating cavity is formed between the insulation layer and the vessel body. The outer wall of the insulation layer is provided with an oil inlet and an oil outlet.

[0012] Preferably, the lid is fixed to the top of the vessel body by bolts, the feed pipe is located at the top of the lid, the discharge pipe is located at the bottom of the vessel body, and a valve is installed inside the discharge pipe.

[0013] Preferably, the scraper is made of wear-resistant polymer material or elastic metal material.

[0014] Preferably, the linear actuator is an electric actuator or a pneumatic actuator.

[0015] Compared with the prior art, the present invention provides a reaction vessel for magnesium sulfate production, which has the following beneficial effects: 1. By setting up a wall scraping component, the attached material on the inner wall of the vessel can be effectively scraped off, avoiding the impact of material scaling on heat transfer and reaction uniformity. By setting a pressure detection unit between the translation unit and the scraper fixing frame, the contact pressure between the scraper and the inner wall can be monitored in real time, providing a data basis for adaptive adjustment.

[0016] 2. By calculating the instantaneous pressure change coefficient through the controller and controlling the retraction of the translation unit when the coefficient exceeds the threshold, the scraper blade can be effectively prevented from being damaged by strong collision with the material on the inner wall, thus extending the service life of the scraper blade.

[0017] 3. By gradually moving closer to readjust the scraper position, the scraping function can be restored after avoiding severe collisions, thus balancing safety and scraping efficiency. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the installation structure between the stirring assembly and the wall scraping assembly of the present invention; Figure 3 This is a schematic diagram of the wall scraping assembly structure of the present invention; Figure 4 For the present invention Figure 3 A magnified structural diagram at point A; Figure 5 This is a schematic diagram of the operation flow of the wall scraping component of the present invention.

[0019] In the diagram: 1. Vessel body; 2. Vessel lid; 3. Feed pipe; 4. Discharge pipe; 5. Stirring assembly; 51. Central shaft; 52. Stirring rod mounting bracket; 53. Stirring rod; 54. Motor; 6. Wall scraper assembly; 61. Translation unit; 62. Scraper fixing bracket; 63. Mounting base; 64. Scraper; 65. Guide column; 7. Fixing sleeve; 71. Mounting groove; 8. Pressure detection unit; 9. Insulation layer; 91. Oil inlet; 92. Oil outlet. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0021] 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.

[0022] Reference Figures 1-4 A reaction vessel for magnesium sulfate production includes a vessel body 1, a vessel lid 2, a feed pipe 3, a discharge pipe 4, a stirring assembly 5, and at least one wall scraping assembly 6. The vessel body 1 is a vertical cylindrical structure with an opening at the top. The vessel lid 2 is bolted to the opening at the top of the vessel body 1, forming a sealed reaction space. The feed pipe 3 is located at the top of the vessel lid 2 and is used to feed the reaction raw materials required for magnesium sulfate production, such as magnesium oxide powder, sulfuric acid solution, or other auxiliary additives, into the vessel body 1. The discharge pipe 4 is located at the bottom of the vessel body 1 and is used to discharge the magnesium sulfate slurry or finished solution after the reaction is completed. A valve is installed inside the discharge pipe 4 to control the discharge flow rate and its on / off function. The vessel body 1 and vessel lid 2 are preferably made of corrosion-resistant stainless steel, such as 316L stainless steel, to resist acidic or salt corrosion that may occur during the reaction of the magnesium sulfate slurry, ensuring the safety and reliability of the equipment during long-term use.

[0023] The stirring assembly 5 is installed on the vessel cover 2 and is used to mechanically stir the materials inside the vessel body 1, promoting thorough mixing and mass transfer between the solid and liquid phases or liquid reactants. The wall scraping assembly 6 is installed in conjunction with the stirring assembly 5 and is used to scrape the inner wall of the vessel body 1 during stirring, removing scale or deposits adhering to the inner wall. Specifically, the wall scraping assembly 6 includes a translation unit 61, a scraper fixing bracket 62, a mounting base 63, a scraper 64, and a pressure detection unit 8. The translation unit 61 is fixedly connected to the stirring rod 53 of the stirring assembly 5 via the mounting base 63. The mounting base 63 is preferably an L-shaped or U-shaped metal bracket, one end of which is fixed to the side of the stirring rod 53 by bolts or welding, and the other end provides a flat mounting surface for fixing the housing of the translation unit 61. The output shaft of the translation unit 61 extends horizontally, and its end is fixedly connected to the scraper fixing bracket 62. The scraper holder 62 is generally a long, strip-shaped plate structure. A slot extending along its length is opened on the side away from the translation unit 61. The scraper 64 is embedded in this slot, and is secured in the slot by multiple evenly distributed bolts passing through the side wall of the scraper holder 62, preventing the scraper 64 from shifting or falling off during stirring. A pressure detection unit 8 is installed at the connection between the translation unit 61 and the scraper holder 62. It is used to detect the contact pressure between the scraper 64 and the inner wall of the vessel 1 in real time and transmit the pressure signal to an external controller.

[0024] Reference Figure 5Before the stirring operation begins, the controller sends a control signal to drive the translation unit 61 to extend. This extension, via the output shaft, pushes the scraper holder 62, along with the scraper 64, towards the inner wall of the vessel 1. The scraper 64 gradually approaches until it makes slight contact with the inner wall surface or reaches a preset initial contact pressure value. Then, the stirring assembly 5 is activated, causing the wall scraping assembly 6 to rotate around the central axis of the vessel 1 along with the stirring rod 53. During rotation, the scraper 64 scrapes away the material adhering to the inner wall. During stirring, the pressure detection unit 8 uses high-frequency sampling to detect the contact pressure between the scraper 64 and the inner wall in real time and transmits the pressure data to the controller. The controller has a built-in data processing module that performs time-series analysis on the received pressure data and calculates the instantaneous pressure change coefficient. This coefficient can be defined as the ratio of the absolute value of the pressure difference between adjacent sampling times to the time interval, or the pressure variance within a sliding window can be used as an indicator of the severity of pressure fluctuations. The controller compares the calculated instantaneous pressure change coefficient with a pre-stored threshold value. If the coefficient exceeds the set threshold, it indicates an abnormally violent collision between the scraper 64 and the inner wall. At this point, the controller immediately issues a retraction command, controlling the output shaft of the translation unit 61 to retract, moving the scraper fixing bracket 62 and the scraper 64 away from the inner wall of the vessel 1. This disengages the scraper 64 from the inner wall, preventing damage to the scraper 64 or scratches on the inner wall from continuous collisions. After the translation unit 61 retracts to a safe position, the controller controls the translation unit 61 to gradually approach the scraper 64 towards the inner wall again. Gradual approach means that the controller drives the translation unit 61 to extend in multiple small steps, maintaining a stable position for a short period after each step. If the instantaneous pressure change coefficient exceeds the set threshold again during this process, the extension is immediately stopped and the scraper retracts a certain distance. If the pressure data is stable, the extension continues to the next step until the scraper 64 returns to a working position capable of effectively scraping the wall.

[0025] Through the aforementioned adaptive adjustment process, the wall scraping assembly 6 can effectively avoid the risk of severe collisions caused by material particle jamming or sudden changes in material viscosity while ensuring the wall scraping effect, significantly improving the service life of the scraper 64 and the reliability of equipment operation. It should be noted that the controller in this embodiment is a programmable logic controller or a microcontroller control unit, which internally stores control logic programs and set threshold parameters. The specific value of this threshold can be calibrated and optimized through a limited number of experiments based on the material characteristics, stirring speed, and the gap between the scraper 64 and the inner wall in actual production.

[0026] Furthermore, regarding the specific selection of the translation unit 61, it can be a linear module or a linear actuator. A linear module typically includes a slide table, a lead screw, and a drive motor, offering advantages such as high positioning accuracy and controllable stroke. Linear actuators, on the other hand, include electric actuators, pneumatic actuators, or hydraulic actuators, featuring compact structure and fast response. In this embodiment, considering that the magnesium sulfate production environment is typically dusty or humid, an electric actuator is preferentially selected as the translation unit 61, offering a higher protection level and facilitating precise displacement control.

[0027] Furthermore, to optimize the connection structure between the translation unit 61 and the scraper fixing bracket 62, and to facilitate the installation of the pressure detection unit 8, the output shaft of the translation unit 61 is fixedly connected to the scraper fixing bracket 62 via a fixing sleeve 7. The fixing sleeve 7 is a cylindrical or square cylindrical component, with one end having an internal threaded hole or flange for threaded or flanged connection to the end of the output shaft of the translation unit 61; the other end of the fixing sleeve 7 is fixed to the back of the scraper fixing bracket 62 by welding or bolting. A mounting groove 71 is provided on the side of the fixing sleeve 7 near the scraper fixing bracket 62. This mounting groove 71 is a circular or square recess, the depth and size of which match the shape of the pressure detection unit 8. The pressure detection unit 8 is embedded in the mounting groove 71, and the sensing surface of the pressure detection unit 8 is in close contact with the back of the scraper fixing bracket 62 to ensure accurate sensing of the axial force between the output shaft of the translation unit 61 and the scraper fixing bracket 62. This force is proportional to the radial contact pressure experienced by the scraper 64. The signal cable of the pressure detection unit 8 can be routed along the outside of the housing of the translation unit 61 and led to the controller outside the vessel body 1 via a slip ring or cable chain to achieve signal transmission during rotation.

[0028] Regarding the selection of the pressure detection unit 8, in this embodiment, the pressure detection unit 8 is preferably a thin-film pressure sensor. Thin-film pressure sensors have the advantages of thinness, fast response speed, high sensitivity, and strong overload resistance, making them suitable for installation in a narrow mounting slot 71. The sensitive area of ​​the thin-film pressure sensor can convert the applied pressure into a change in resistance or voltage signal. After amplification and filtering by subsequent signal conditioning circuitry, the signal is transmitted to the analog input port of the controller for analog-to-digital conversion and data processing. Of course, in other embodiments, the pressure detection unit 8 can also be a small piezoelectric force sensor or a strain gauge force sensor, as long as it can meet the requirement of stable pressure signal output under rotating conditions.

[0029] In addition, to enhance the motion stability of the scraper holder 62 during translation and prevent swaying or vibration due to its large overhang length, multiple guide posts 65 are fixed on the scraper holder 62. Each guide post 65 is a slender, round rod, with one end fixed to the back of the scraper holder 62 by thread or welding, and the other end passing through a corresponding circular hole in the stirring rod 53. The guide post 65 and the circular hole on the stirring rod 53 are in clearance fit, allowing the guide post 65 to slide freely horizontally relative to the stirring rod 53 along with the scraper holder 62, while simultaneously guiding and constraining the movement of the scraper holder 62, preventing it from deviating perpendicular to the translation direction. The guide posts 65 are made of smooth stainless steel round bars with a hard chrome plating on the outer surface to reduce sliding friction resistance with the circular hole.

[0030] Regarding the specific structure of the stirring assembly 5, the stirring assembly 5 includes a central shaft 51, multiple stirring rod mounting brackets 52, multiple stirring rods 53, and a motor 54. The central shaft 51 is a long cylindrical shaft, which is vertically mounted downwards at the center of the vessel cover 2. Specifically, the center of the vessel cover 2 is provided with a bearing seat and a sealing device. The upper end of the central shaft 51 passes through the bearing seat and is rotatably engaged with the vessel cover 2 through a rolling bearing, while the lower end of the central shaft 51 extends into the interior of the vessel body 1. The multiple stirring rod mounting brackets 52 are all annular or disc-shaped components, which are evenly distributed and fixedly mounted on the central shaft 51, and are circumferentially fixed to the central shaft 51 by key connections or set screws. Multiple stirring rods 53 are fixedly mounted in a circumferential array on the outer periphery of each stirring rod mounting bracket 52. The stirring rods 53 extend outwards along the horizontal radial direction, and their outer ends are free ends or equipped with stirring blades. In this embodiment, each stirring rod mounting bracket 52 is equipped with three stirring rods 53, with an included angle of 120 degrees between adjacent stirring rods 53, to achieve omnidirectional stirring of materials at different heights and radial positions inside the vessel body 1. A motor 54 is fixed to the top of the vessel cover 2, and the output shaft of the motor 54 extends downwards, coaxially connected to the upper end of the central shaft 51 via a coupling. The motor 54 is a variable frequency speed-regulating motor, allowing adjustment of the stirring speed according to the reaction process requirements. During operation, the motor 54 drives the central shaft 51 to rotate, thereby causing all stirring rod mounting brackets 52 and stirring rods 53 to rotate together. The stirring rods 53 apply shearing and mixing action to the materials. The wall scraping assembly 6 is fixed to one or more stirring rods 53 via a mounting base 63 and rotates with the stirring rods 53, thus achieving synchronous wall scraping and stirring actions.

[0031] In addition, to meet the heating or insulation requirements that may be needed during the magnesium sulfate reaction, an insulation layer 9 integrally formed with the reactor body 1 is provided on the periphery of the reactor body 1. The insulation layer 9 has a jacketed structure, fitted onto the outer wall of the reactor body 1, forming a closed heating chamber between the inner wall of the insulation layer 9 and the outer wall of the reactor body 1. One side of the outer wall of the insulation layer 9 has an oil inlet 91, and the other side has an oil outlet 92. Both the oil inlet 91 and the oil outlet 92 are connected to an external heat transfer oil circulation heating system via pipes. When it is necessary to heat the material inside the reactor body 1, high-temperature heat transfer oil enters the heating chamber from the oil inlet 91, exchanges heat with the wall of the reactor body 1, and transfers heat to the material inside the reactor body 1. After heat exchange, the heat transfer oil flows out from the oil outlet 92 and returns to the heating system for reheating. By setting up the insulation layer 9, the reaction temperature can be precisely controlled, improving the efficiency and quality of the magnesium sulfate crystallization or reaction process.

[0032] Regarding the material selection for the scraper blade 64, to balance scraping performance and protection of the inner wall, the scraper blade 64 is made of either a wear-resistant polymer material or an elastic metal material. Wear-resistant polymer materials, such as ultra-high molecular weight polyethylene or polytetrafluoroethylene, have the advantages of low friction coefficient, good self-lubrication, and will not scratch the inner metal wall, making them suitable for applications where material adhesion is moderate and the material is sensitive to metal ion contamination. Elastic metal materials, such as spring steel or stainless steel sheet, possess certain elasticity and wear resistance after heat treatment, making them suitable for applications where materials adhere tightly and require greater scraping force. The cross-sectional shape of the scraper blade 64 is preferably rectangular or trapezoidal, and its edges in contact with the inner wall can be rounded or beveled to reduce stress concentration and prevent scratches.

[0033] 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 reaction vessel for the production of magnesium sulfate, comprising a vessel body (1), a vessel lid (2), a feed pipe (3), a discharge pipe (4), a stirring assembly (5), and at least one wall scraping assembly (6), characterized in that, The wall scraping assembly (6) includes a translation unit (61), a scraper fixing frame (62), a mounting base (63), a scraper (64), and a pressure detection unit (8). The translation unit (61) is fixed to the stirring rod (53) of the stirring assembly (5) through the mounting base (63). The output shaft of the translation unit (61) is fixedly connected to the scraper fixing frame (62). The scraper (64) is embedded in the slot of the scraper fixing frame (62) and fixed with bolts. The pressure detection unit (8) is installed at the connection between the translation unit (61) and the scraper fixing frame (62).

2. The reaction vessel for magnesium sulfate production according to claim 1, characterized in that, The translation unit (61) is a linear module or a linear driver.

3. The reaction vessel for magnesium sulfate production according to claim 1, characterized in that, The output shaft of the translation unit (61) is fixedly connected to the scraper fixing frame (62) through the fixing sleeve (7). The fixing sleeve (7) has an installation groove (71) on the side close to the scraper fixing frame (62), and the pressure detection unit (8) is embedded in the installation groove (71).

4. A reaction vessel for magnesium sulfate production according to claim 3, characterized in that, The pressure detection unit (8) is a thin-film pressure sensor.

5. A reaction vessel for magnesium sulfate production according to claim 1, characterized in that, The scraper fixing frame (62) is also fixed with a plurality of guide posts (65), and the other ends of the plurality of guide posts (65) pass through the round holes on the corresponding stirring rods (53).

6. A reaction vessel for magnesium sulfate production according to claim 1, characterized in that, The stirring assembly (5) includes a central shaft (51), multiple stirring rod mounting brackets (52), multiple stirring rods (53), and a motor (54). The central shaft (51) is installed vertically downward at the center of the vessel cover (2). The multiple stirring rod mounting brackets (52) are evenly distributed and fixedly mounted on the central shaft (51). The multiple stirring rods (53) are arranged in a circumferential array on each stirring rod mounting bracket (52). The motor (54) is fixed to the top of the vessel cover (2), and the output shaft of the motor (54) is connected to the end of the central shaft (51) through a coupling.

7. A reaction vessel for magnesium sulfate production according to claim 1, characterized in that, The outer periphery of the vessel body (1) is also provided with an insulation layer (9) integrally formed with the vessel body (1), and a heating cavity is formed between the insulation layer (9) and the vessel body (1). The outer wall of the insulation layer (9) is provided with an oil inlet (91) and an oil outlet (92).

8. A reaction vessel for magnesium sulfate production according to claim 1, characterized in that, The lid (2) is fixed to the top of the body (1) by bolts. The feed pipe (3) is located on the top of the lid (2). The discharge pipe (4) is located at the bottom of the body (1), and a valve is installed inside the discharge pipe (4).

9. A reaction vessel for magnesium sulfate production according to claim 1, characterized in that, The scraper (64) is made of wear-resistant polymer material or elastic metal material.

10. A reaction vessel for magnesium sulfate production according to claim 2, characterized in that, The linear actuator is an electric actuator or a pneumatic actuator.

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