An apparatus for preparing a titanic acid gel and a system for preparing nano-titanium white

Abstract

The utility model relates to titanium dioxide preparation device technical field especially relates to a device and preparation nanometer titanium dioxide of preparation titanogel. Include: reaction container, stirring mechanism, vortex disperser, set up in reaction container bottom, including turbine, perforated screen and umbrella -like diffusion head, for dispersing into liquid alkali and even injection titanyl sulfate solution in fine flow, interface, with vortex disperser connects, for conveying liquid alkali, through the vortex disperser of reaction container bottom realizes the even injection of liquid alkali, avoids local concentration too high, improves mixing efficiency, reduces particle agglomeration, ensures that titanogel particle size distribution is even, and further ensures that nanometer titanium dioxide particle size distribution is even, the core innovation of the utility model lies in the traditional top drop -wise mixing mode is innovated as bottom vortex injection mode, and the mixing dynamics characteristics of reaction liquid are fundamentally changed.

Description

Technical Field

[0001] This utility model relates to the technical field of titanium dioxide preparation equipment, and in particular to an apparatus for preparing titanate gel and a system for preparing nano-titanium dioxide. Background Technology

[0002] Nano-titanium dioxide (TiO2), also known as nano-titanium white, is widely used in environmental pollution control, solar cells, antibacterial materials, and energy storage due to its excellent photocatalytic performance, high chemical stability, and unique semiconductor properties. As an important functional material, the application of nano-titanium white has expanded from traditional coatings and plastic additives to cutting-edge fields such as new energy, environmental governance, and biomedicine. In the new energy field, nano-titanium white serves as the photoanode material in dye-sensitized solar cells (DSSC), where its particle size distribution and pore structure directly affect the cell's photoelectric conversion efficiency. In environmental governance, its photocatalytic properties can be used to degrade organic pollutants and purify air and water. In the biomedical field, the antibacterial properties and good biocompatibility of nano-titanium white demonstrate its great potential in antibacterial coatings and drug carriers.

[0003] Among numerous preparation methods, the inorganic sol-gel method has attracted much attention due to its simple process, low cost, and ease of large-scale production. This method typically uses titanium oxysulfate (TiOSO4) as the titanium source, reacting it with alkaline precipitants such as liquid alkali (e.g., NaOH) to form a sol through a hydrolysis-condensation process. After aging, washing, gelation, drying, and calcination, nano-titanium dioxide particles are obtained. The intermediate product, titanate gel particles, plays a crucial role in the preparation of nano-titanium dioxide; that is, the preparation of titanate gel particles determines the particle size of nano-titanium dioxide.

[0004] However, the traditional sol-gel method for preparing nano-titanium dioxide has the following key technical problems: 1. Hybrid Dynamic Limitations: In traditional dropwise addition methods, the mixing time constant of liquid alkali and titanium oxysulfate solution is approximately 1-10 seconds, while the characteristic time of the hydrolysis reaction is only in the millisecond range. This timescale mismatch leads to local pH fluctuations exceeding 2 units in the reaction system, resulting in severe concentration gradients. The particle size distribution index (PDI) in sols prepared by traditional methods is as high as 0.35-0.5, while the PDI of an ideal monodisperse system is between 0.05 and 0.1.

[0005] 2. Complexity of Agglomeration Mechanism: Particle agglomeration is dually regulated by "chemical affinity and physical forces." The uneven distribution of hydroxyl groups (-OH) on the surface of the colloidal particles generated by hydrolysis forms a hydrogen bond network under the action of van der Waals forces. During the drying process, capillary forces (up to 100 MPa) further intensify hard agglomeration. The primary particle size of nano-titanium dioxide agglomerates prepared by traditional methods is about 20 nm, but the agglomerate size can reach more than 500 nm, resulting in a specific surface area loss of more than 60%.

[0006] 3. Sensitivity to process parameters: The hydrolysis reaction rate is highly sensitive to parameters such as temperature, concentration, and stirring intensity. If the reaction temperature fluctuates by ±2℃, the coefficient of variation (CV) of the product particle size distribution will increase from 15% to 30%, resulting in significant performance differences between batches.

[0007] 4. Limitations of post-processing: To improve dispersibility, traditional processes often employ centrifugal classification, ultrasonic dispersion, or the addition of surfactants. These steps not only increase production costs but may also introduce impurities or damage the crystal structure.

[0008] In recent years, researchers have attempted to optimize the mixing process using the following methods, but shortcomings remain, such as: 1. Microfluidic mixing technology: Based on the principle of laminar diffusion, molecular-level mixing is achieved in micron-level channels, and the mixing time can be shortened to the microsecond level. However, this technology has three major engineering challenges: the contradiction between channel size and production throughput leads to extremely low Reynolds numbers, resulting in decreased mixing efficiency after scale-up; high-viscosity reaction liquids easily cause channel blockage, resulting in short cleaning cycles; and high equipment manufacturing costs make it difficult to adapt to large-scale production.

[0009] 2. Ultrasonic-assisted technology: This technology utilizes the cavitation effect to generate localized high temperature and pressure and microjets, which can instantly destroy aggregates. However, the non-uniformity of energy input leads to a wider particle size distribution; the shock wave generated by the collapse of cavitation bubbles can introduce crystal defects (such as Ti). 3+ Impurities).

[0010] 3. Surface modification technology: Adding surfactants such as polyvinylpyrrolidone (PVP) and sodium dodecylbenzenesulfonate (SDBS) can inhibit agglomeration through steric hindrance. However, organic residues can occupy catalytically active sites. Furthermore, surfactant removal requires additional high-temperature calcination, leading to increased energy consumption.

[0011] Based on the above, existing technologies for preparing nano-titanium dioxide have several technical problems that urgently need to be solved, including high local concentration gradients, uneven particle size, particle agglomeration, poor dispersibility, complex post-processing procedures, and high production costs. Utility Model Content

[0012] To solve the above-mentioned technical problems, this utility model provides an apparatus for preparing titanate gel, comprising: Reaction vessel; The stirring mechanism includes a stirring motor and a stirring paddle, one end of which extends into the reaction vessel and the other end is connected to the stirring motor located above the reaction vessel. A vortex disperser, located at the bottom of the reaction vessel, includes a turbine, a porous filter, and an umbrella-shaped diffuser head, used to disperse liquid alkali into a fine stream and inject it uniformly into the titanium oxysulfate solution; An interface for connecting to a vortex disperser for conveying liquid alkali; Uniform injection of liquid alkali is achieved through a vortex disperser at the bottom of the reaction vessel, avoiding excessively high local concentrations, improving mixing efficiency, reducing particle agglomeration, and ensuring uniform particle size distribution of titanate gel.

[0013] Furthermore, the reaction vessel is provided with a material inlet at the top for injecting titanium oxysulfate solution.

[0014] Furthermore, the reaction vessel has a double-layer jacketed design, with an inner layer of stainless steel, an outer layer of polycarbonate, and a jacket of heat-conducting oil.

[0015] Furthermore, annular ribs are provided on the inner wall of the reaction vessel. When the stirring paddle rotates, the annular ribs can disrupt the boundary layer flow, generate secondary eddies, and prevent the formation of stirring "dead zones".

[0016] Furthermore, the bottom of the reaction vessel is also provided with a discharge port for conveying the reacted titanate gel out of the device from the reaction vessel.

[0017] Furthermore, the bottom sidewall of the reaction vessel adopts a conical angle structure with an angle of 30°-60° with the ground.

[0018] Furthermore, the reaction vessel is also equipped with a nitrogen purging port, a pH electrode interface, and a temperature sensor interface, which, together with the discharge port, enable comprehensive monitoring and control.

[0019] Furthermore, the stirring mechanism includes a stirring motor and a stirring paddle, used for mixing the reaction liquid.

[0020] Furthermore, the stirring paddle is one or a combination of blade type, anchor type or spiral type, providing moderate shear force to promote uniform sol formation and avoid excessive stirring that introduces bubbles or crystal defects.

[0021] Furthermore, when the stirring paddle is anchor-type, it provides stirring shear force, promotes uniform sol formation, avoids excessive stirring that introduces bubbles or crystal defects, and works in conjunction with the vortex disperser.

[0022] Furthermore, the edge of the anchor-type stirring paddle is provided with micro-serrations, with a tooth height of 1-2 mm and a spacing of 5-10 mm. The micro-serrations generate high-frequency eddies, which further break up the liquid alkali clusters and achieve molecular-level dispersion.

[0023] Furthermore, the stirring paddle rotates at a speed of 200-800 rpm.

[0024] Furthermore, the backward bend angle of the blade-type agitator is 40°-50°.

[0025] Furthermore, the stirring mechanism also includes an auxiliary vortex generator, which consists of 4-6 radial guide plates on the stirring shaft of the stirring paddle. When the rotation speed exceeds 400 rpm, a Karman vortex street is generated behind the guide plates, producing periodic disturbances that can effectively break the laminar flow state formed by stirring and significantly reduce the mixing time.

[0026] Furthermore, during use, the vortex disperser forms a spiral guide layer inside, which is used to tangentially accelerate the liquid flow to form a vortex, thereby enhancing the dispersion effect of the liquid alkali, achieving molecular-level mixing, and reducing the difference in nucleation rate.

[0027] Furthermore, the turbine has 4-8 blades with a blade inclination angle of 15°-45° to optimize eddy current generation efficiency and ensure sufficient dispersion of liquid alkali.

[0028] Furthermore, the turbine in the vortex disperser preferably has 4 blades with a blade inclination angle of 25° to optimize vortex generation efficiency and ensure that the liquid alkali is fully dispersed.

[0029] Furthermore, the turbine in the vortex disperser preferably has 6 blades, including 3 forward-curved blades and 3 backward-curved blades, with a blade inclination angle of 30°. This asymmetrical arrangement can generate a periodically changing pressure field, promoting the radial dispersion of liquid alkali.

[0030] Furthermore, the blade surface has grooves of 50-100 μm, which further increases the mass transfer coefficient at the liquid-solid interface and accelerates the reaction between liquid alkali and titanium oxysulfate.

[0031] Furthermore, the porous filter screen has a pore size of 50-200 μm to divide the liquid alkali into fine streams, avoiding local concentration gradients caused by large droplets.

[0032] Furthermore, the porous filter adopts a dual-layer composite filter structure: the lower layer is a 200μm first filter and the upper layer is a 100μm second filter, realizing a two-stage dispersion of "coarse segmentation-fine dispersion", which further avoids excessive local concentration gradients caused by large droplets.

[0033] Furthermore, the double-layer composite filter screen is also provided with a support structure, which adopts a honeycomb porous plate with a porosity of 50-70%, which ensures mechanical strength, reduces fluid resistance, and reduces pressure loss.

[0034] Furthermore, the umbrella-shaped diffuser head has an inclination angle of 30°-60° to further disperse the liquid alkali, ensuring it evenly covers the reaction area and preventing local oversaturation.

[0035] Furthermore, the edge of the umbrella-shaped diffuser is provided with serrated guide grooves to generate micro-vortices, further breaking up the droplets and increasing the diffusion coefficient of the liquid alkali in the reaction solution.

[0036] Furthermore, the diameter of the umbrella-shaped diffuser head on the side closest to the porous filter is greater than or equal to the diameter of the porous filter, in order to prevent a decrease in the flow rate of the liquid alkali stream delivered from the porous filter and to avoid the re-mixing of multiple streams, thereby reducing reaction efficiency and droplet dispersion.

[0037] Furthermore, the device also includes a check valve to prevent backflow of the reaction liquid.

[0038] Furthermore, the check valve is one or a combination of spring-loaded or ball-type check valves, used to prevent backflow of the reaction liquid from contaminating the delivery system and to ensure the quantitative addition of liquid alkali.

[0039] Furthermore, the device also includes a peristaltic pump connected to the interface for metering alkaline solution into the vortex disperser.

[0040] Furthermore, the device also includes a temperature control device connected to the temperature sensor interface, used to maintain the reaction temperature, control the hydrolysis-condensation rate, and avoid uneven particle size caused by temperature fluctuations.

[0041] Furthermore, the reaction temperature is controlled at 25-60℃.

[0042] Furthermore, the interface is detachable, which facilitates cleaning and replacement, reduces the risk of blockage, and improves the maintainability and service life of the device.

[0043] Furthermore, the interface is a Luer Lock quick-release structure.

[0044] This invention also provides a system for preparing nano-titanium dioxide, the system comprising the apparatus described above for preparing titanate gel.

[0045] Furthermore, the system also includes a washing device, a gelling device, a drying device, and a calcining device.

[0046] Furthermore, the washing device includes a Buchner funnel.

[0047] Furthermore, the gelation apparatus includes a reaction vessel and a temperature control device.

[0048] Furthermore, the drying device is an oven.

[0049] Furthermore, the calcination apparatus is a muffle furnace.

[0050] The beneficial effects of this utility model are as follows: 1. This utility model provides an apparatus for preparing titanate gel. It includes: a reaction vessel; a stirring mechanism including a stirring motor and a stirring paddle, one end of the stirring paddle extending into the reaction vessel and the other end connected to the stirring motor located above the reaction vessel; a vortex disperser disposed at the bottom of the reaction vessel, including a turbine, a porous filter screen, and an umbrella-shaped diffuser head, used to disperse liquid alkali into a fine stream and uniformly inject it into a titanium oxysulfate solution; and an interface connected to the vortex disperser for conveying liquid alkali. The vortex disperser at the bottom of the reaction vessel achieves uniform injection of liquid alkali, avoiding excessively high local concentrations, improving mixing efficiency, reducing particle agglomeration, ensuring uniform particle size distribution of the titanate gel, and thus ensuring uniform particle size distribution of nano-titanium dioxide. The core innovation of this utility model lies in transforming the traditional top-drop mixing mode into a bottom-vortex injection mode, which fundamentally changes the hybrid dynamic characteristics of the reaction liquid. 2. This invention provides a low-energy, high-precision apparatus for preparing titanate gel, which can achieve instantaneous homogenization of reactants at the molecular scale, thereby eliminating local concentration gradients and avoiding particle size inhomogeneity caused by explosive nucleation; inhibiting particle agglomeration and improving the monodispersity of the sol; simplifying the process flow, reducing reliance on post-processing, and lowering production costs. Specifically, the vortex disperser located at the bottom of the reaction vessel proposed in this invention uses spiral guidance, porous filter segmentation, and umbrella-shaped diffuser to uniformly distribute liquid alkali at the bottom of the vessel in the form of a spray, making the contact between liquid alkali and titanium oxysulfate more uniform and significantly improving the mixing efficiency. This avoids the phenomenon of excessively high local concentrations and the formation of large particles or agglomeration caused by direct addition through the liquid addition tube in the prior art, thereby achieving uniform particle size distribution control. It fundamentally solves the technical problems of high local concentration gradients, uneven particle size, particle agglomeration, poor dispersibility, complex post-processing flow, and high production costs in the preparation of titanate gel in the prior art, providing a reliable solution for the large-scale preparation of nano-titanium dioxide. Attached Figure Description

[0051] Figure 1 This is a schematic cross-sectional view of the apparatus for preparing titanate gel according to the present invention; Figure 2 This is a cross-sectional view of the reaction vessel of this utility model, which has a conical bottom structure. Figure 3 for Figure 1 A magnified view of a section at point A in the middle; Figure 4 This is a schematic diagram of the structure of the stirring paddle of this utility model with micro-serrations; The labels in the diagram are named as follows: 1. Reaction vessel; 11. Stainless steel layer; 12. Polycarbonate layer; 13. Heat transfer oil layer; 21. Stirring motor; 22. Stirring paddle; 221. Micro-serration; 31. Turbine; 32. Porous filter screen; 33. Umbrella-shaped diffuser head; 4. Check valve; 5. Interface. Detailed Implementation

[0052] Example 1 like Figure 1 As shown, this utility model provides an apparatus for preparing titanate gel, comprising: Reaction vessel 1; The stirring mechanism includes a stirring motor 21 and a stirring paddle 22. One end of the stirring paddle 22 extends into the reaction vessel 1, and the other end is connected to the stirring motor 21 located above the reaction vessel 1. A vortex disperser, located at the bottom of the reaction vessel 1, includes, from bottom to top, a turbine 31, a porous filter 32, and an umbrella-shaped diffuser 33, used to disperse liquid alkali into a fine stream and uniformly inject it into the titanium oxysulfate solution; Interface 5 is connected to the vortex disperser and is used to deliver liquid alkali into the vortex disperser. After being stirred by the turbine 31, it is dispersed into a fine stream by the porous filter 32 and finally enters the reaction vessel 1 through the umbrella-shaped diffuser 33 to react with the titanium oxysulfate solution located inside the reaction vessel 1. The liquid alkali is uniformly injected through the vortex disperser at the bottom of reaction vessel 1, avoiding excessively high local concentrations, improving mixing efficiency, reducing particle agglomeration, ensuring uniform particle size distribution of titanate gel, and thus ensuring uniform particle size distribution of subsequent nano titanium dioxide.

[0053] In this embodiment, a material inlet is provided above the reaction vessel 1 for injecting titanium oxysulfate solution into the reaction vessel 1.

[0054] In some embodiments, such as Figure 3 As shown, Figure 1 The enlarged view at point A shows that the reaction vessel 1 has a double-layer jacket design. The inner layer is a stainless steel layer 11, the outer layer is a polycarbonate layer 12, and the interlayer is a heat-conducting oil layer 13. The heat-conducting oil layer 13 is circulated with any commercially available heat-conducting oil. This double-layer jacket design enables precise temperature control and avoids local temperature gradients affecting the rate of titanate gel preparation.

[0055] In some embodiments, a plurality of annular ribs with a height of 5 mm and a spacing of 20 mm are provided on the inner wall of the reaction vessel 1. When the stirring paddle 22 rotates, the annular ribs can disrupt the boundary layer flow and generate secondary eddies, thereby increasing the fluid shear rate near the inner wall of the reaction vessel 1 and preventing the formation of a stirring "dead zone".

[0056] In this embodiment, the bottom of the reaction vessel 1 is also provided with a discharge port for conveying the reacted nano-titanium dioxide from the reaction vessel 1 out of the device. In some embodiments, such as... Figure 2 As shown, the bottom sidewall of the reaction vessel 1 adopts a conical structure with an angle of 30° to the ground. Compared with the flat bottom design, the amount of material residue can be effectively reduced and the discharge time can be shortened. At the same time, the conical surface can guide the vortex to expand upward and enhance axial mixing.

[0057] Furthermore, in some embodiments, in addition to the discharge port provided above the reaction vessel 1, a nitrogen purging port, a pH electrode interface, a temperature sensor interface, and an interface 5 connected to the discharge port and the vortex disperser provided at the bottom are also provided to realize comprehensive monitoring and control of the materials in the device.

[0058] like Figure 1 As shown, the stirring mechanism includes a stirring motor 21 and a stirring paddle 22, which are used to mix the reaction liquid.

[0059] In this embodiment, the stirring paddle 22 is any commercially available anchor-type stirring paddle, which provides stirring shear force, promotes uniform sol formation, avoids excessive stirring that introduces bubbles or crystal defects, and works in conjunction with the vortex disperser.

[0060] In some embodiments, such as Figure 4 As shown, multiple micro-serrations 221 are added to the edge of any side of the anchor-type stirring paddle 22. The tooth height is 1-2 mm and the spacing is 5-10 mm. The micro-serrations generate high-frequency eddies, which further break up the liquid alkali clusters and achieve molecular-level dispersion.

[0061] In some embodiments, the stirring paddle 22 may also be blade-type or spiral-type.

[0062] In this embodiment, the rotational speed of the stirring paddle 22 is controlled between 400-600 rpm.

[0063] In some embodiments, the stirring structure adopts a "main stirring-auxiliary vortex" composite stirring mode, including a main stirring paddle and an auxiliary vortex generator.

[0064] The main stirring paddle is a switchable stirring paddle 22. During the reaction stage, i.e., the titanate gel growth stage, it switches to an anchor-type stirring paddle to generate strong shear force and inhibit particle agglomeration; then a blade-type stirring paddle is used to maintain gentle stirring, reduce energy consumption, and further save production costs. The preferred backbend angle of the blade-type stirring paddle is 45°.

[0065] The auxiliary vortex generator consists of four radial guide plates on the stirring shaft of the stirring paddle 22. When the rotation speed exceeds 400 rpm, a Karman vortex street is generated behind the guide plates, producing periodic disturbances that can effectively break the laminar flow state formed by stirring, thereby significantly reducing the mixing time again.

[0066] In this embodiment, the vortex disperser, as the core component of the device, has made innovative breakthroughs in the technical bottleneck of traditional mixing equipment through its structure and location. It is set at the bottom of the reaction vessel 1 and includes a turbine 31, a porous filter 32 above the turbine, and an umbrella-shaped diffuser 33 above the porous filter 32. Liquid alkali enters the vortex disperser through the interface 5, is stirred by the turbine 31, dispersed into a fine stream by the porous filter 32, and finally enters the reaction vessel 1 through the umbrella-shaped diffuser 33 to participate in the reaction.

[0067] like Figure 1 As shown, in this embodiment, the turbine 31 in the vortex disperser has 4 blades with a blade inclination angle of 25° to optimize vortex generation efficiency and ensure sufficient dispersion of liquid alkali. In some embodiments, the number of blades and the blade inclination angle can be adjusted according to actual production conditions, controlling the number of blades to be 4-8 and the blade inclination angle to be 15°-45°. For example, if the number of blades is optimized to 6, including 3 forward-curved blades and 3 backward-curved blades with a blade inclination angle of 30°, this asymmetrical arrangement can generate a periodically changing pressure field, promoting the radial dispersion of liquid alkali.

[0068] Furthermore, in some embodiments, the blade surface is microtextured to create grooves with a depth of 50-100 μm, which further enhances the mass transfer coefficient at the liquid-solid interface and accelerates the reaction between liquid alkali and titanium oxysulfate.

[0069] The porous filter 32 has a pore size of 150 μm, which is used to divide the liquid alkali into micron-sized fine streams to avoid excessive local concentration gradients caused by large droplets.

[0070] In some embodiments, the porous filter 32 adopts a dual-layer composite filter structure: the lower layer is a 200μm first filter and the upper layer is a 100μm second filter. This gradient pore size design can achieve two-stage dispersion of "coarse segmentation-fine dispersion", further avoiding excessive local concentration gradients caused by large droplets. Furthermore, a support structure is provided between the dual-layer composite filter, using a honeycomb porous plate, wherein the porosity is preferably 70%, ensuring mechanical strength while reducing fluid resistance and pressure loss.

[0071] like Figure 1 As shown, the umbrella-shaped diffuser head 33 has an inclination angle of 45° to further disperse the liquid alkali and avoid local oversaturation. In some embodiments, the edge of the umbrella-shaped diffuser head 33 is provided with multiple serrated guide grooves, such as the serrations having a tooth height of 2 mm and a spacing of 5 mm, to generate micro-vortices, further breaking up the droplets and increasing the diffusion coefficient of the liquid alkali in the reaction solution.

[0072] In this embodiment, the diameter of the umbrella-shaped diffuser 33 on the side near the porous filter 32 is equal to the diameter of the porous filter 32, so as to prevent the flow rate of the liquid alkali stream delivered from the porous filter 32 from being reduced, and to avoid multiple streams from merging again, thereby reducing reaction efficiency and droplet dispersion.

[0073] In this embodiment, the device also includes a check valve 4 to prevent the reaction liquid from flowing back.

[0074] The check valve 4 is a ball-type check valve, used to prevent backflow of the reaction liquid and contamination of the delivery system, ensuring the quantitative addition of liquid alkali. In some embodiments, the check valve is a spring-loaded check valve, ensuring unidirectional flow of liquid alkali.

[0075] In some embodiments, the check valve 4 adopts a combined structure, with a spring-type check valve upstream and a ball-type check valve downstream, according to the flow direction of the liquid alkali, providing double protection to ensure zero backflow of the reaction liquid.

[0076] In this embodiment, the device further includes a peristaltic pump, which is connected to the interface 5 and is used to quantitatively deliver alkaline solution into the vortex disperser.

[0077] In some embodiments, the peristaltic pump is a multi-channel flow-type peristaltic pump to achieve pulsed delivery, such as pausing for 0.5 seconds after delivering 1 mL of liquid alkali, so that the liquid alkali is injected in the form of a "pulse vortex", which further improves the uniformity of mixing compared to continuous delivery. In order to ensure that the alkali solution can smoothly enter the reaction vessel 1 from the vortex disperser at the bottom of the reaction vessel 1, the alkali solution can also be pressurized and delivered by a pressurizing device.

[0078] In this embodiment, the device further includes a temperature control system for maintaining the reaction temperature, controlling the hydrolysis-condensation rate, and preventing temperature fluctuations from causing uneven particle size.

[0079] The reaction temperature is controlled at 40-42℃ to avoid uneven particle size caused by excessive temperature changes.

[0080] In this embodiment, the interface 5 is a detachable structure, which facilitates cleaning and replacement, reduces the risk of blockage, and improves the maintainability and service life of the device.

[0081] In some embodiments, the interface 5 directly adopts a Luer Lock quick-release structure, reducing the connection time of traditional couplings. During disassembly, a sealing valve is automatically triggered to prevent material leakage. Simultaneously, the inner wall of the interface 5 can be electrolytically polished (roughness Ra < 0.2 μm) to prevent liquid alkali crystallization and adhesion.

[0082] In the process of producing titanate gel, a titanium oxysulfate solution is added to the device through the material inlet above the reaction vessel 1, and then the stirring mechanism is turned on. In this embodiment, the stirring paddle 22 is an anchor-type stirring paddle, and the rotation speed of the stirring paddle 22 is controlled at 400-600 rpm. Between rpm, a moderate shear force is provided, while avoiding excessive stirring that introduces air bubbles, promotes uniform sol formation after the addition of liquid alkali, or causes crystal defects in the titanate gel due to excessive stirring. After the stirring system stabilizes, the peristaltic pump is turned on, and liquid alkali is quantitatively delivered into the vortex disperser through interface 5. The turbine 31 in the vortex disperser has 4 blades with an inclination angle of 25° to optimize vortex generation efficiency and ensure sufficient dispersion of liquid alkali. The liquid alkali forms a spiral guide layer inside the vortex disperser, and the liquid flow is tangentially accelerated to form vortices, which enhances the dispersion effect of liquid alkali, achieves molecular-level mixing, and reduces the difference in nucleation rate between liquid alkali and titanium oxysulfate in the later stage. The blades with the inclined angle simultaneously accelerate the liquid alkali tangentially again, and the liquid alkali diffuses to the periphery. The accelerated liquid alkali is divided into fine streams by the porous filter 32 to avoid excessive local concentration gradients caused by large droplets, and then diffuses into the reaction vessel 1 through the umbrella-shaped diffuser 33, which can suppress explosive nucleation and obtain monodisperse sol. Figure 1 As shown, the umbrella-shaped diffuser head 33 has an inclination angle of 45°, further dispersing the liquid alkali in the reaction container 1 so that it evenly covers the reaction area and avoids local oversaturation.

[0083] This embodiment also provides a system for preparing nano-titanium dioxide, which, in the order of material flow, includes the above-mentioned apparatus for preparing titanate gel, washing apparatus, gelling apparatus, drying apparatus, and calcination apparatus.

[0084] After the titanate gel is prepared in the above-mentioned apparatus for preparing titanate gel, it is sent to a filtration device through the outlet. In this embodiment, the filtration device is a Buchner funnel. After filtration and washing, it is sent to a gelation device. Under the temperature control of the temperature control device, hydrochloric acid is dripped into the reaction vessel while stirring. Then it is sent to an oven for drying and finally sent to a muffle furnace for calcination to obtain nano-titanium dioxide. Whether nano-titanium dioxide with uniform particle size distribution can be prepared depends on whether the particle size distribution of the prepared titanate gel is uniform.

[0085] Comparative Example 1 Existing technology involves directly adding liquid alkali to a titanium oxysulfate solution, followed by using the washing, sol-gel, drying, and calcining apparatus in the system for preparing nano-titanium dioxide as described in Example 1 to obtain the titanium dioxide product.

[0086] The nano-titanium dioxide products prepared in Example 1 and Comparative Example 1 were compared, and the comparison results are shown in Table 1: Table 1. Performance comparison of titanium dioxide products in Example 1 and Comparative Example 1

[0087] The above experimental results were observed and recorded using transmission electron microscopy (TEM), a technology already in use. Particles prepared by traditional methods contain a large number of chain-like hard agglomerates, while the particles prepared by the device and system provided by this invention are monodisperse, with smooth surfaces and complete crystal forms.

[0088] Therefore, this invention provides a low-energy, high-precision mixing device that can achieve instantaneous homogenization of reactants at the molecular scale, thereby eliminating local concentration gradients and avoiding particle size unevenness caused by explosive nucleation; it also inhibits particle agglomeration, improves the monodispersity of the sol; simplifies the process flow, reduces reliance on post-processing, and lowers production costs. Specifically, the vortex disperser located at the bottom of the reaction vessel 1, proposed in this invention, uses a turbine 31, a porous filter 32 for segmentation, and an umbrella-shaped diffuser 33 for uniform distribution. Liquid alkali is added at the bottom of the vessel in the form of a fine spray, resulting in more uniform contact between the liquid alkali and titanium oxysulfate, significantly improving mixing efficiency. This avoids the phenomenon of excessively high local concentrations leading to large particles or agglomeration caused by direct addition via a liquid addition pipe in existing technologies. This achieves controlled uniform particle size distribution, fundamentally solving the technical problems of high local concentration gradients, uneven particle size, particle agglomeration, poor dispersibility, complex post-processing, and high production costs in the preparation of nano-titanium dioxide using existing technologies. It provides a reliable solution for the large-scale preparation of nano-titanium dioxide.

[0089] Furthermore, the device provided by this utility model can also be applied to different titanium source systems. In addition to the titanium oxysulfate system mentioned in this embodiment, it can also be a titanium tetrachloride system or a tetrabutyl titanate system.

[0090] It should be understood that this utility model is not limited to the content already described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this utility model is limited only by the appended claims.

Claims

1. An apparatus for preparing titanate gel, characterized in that, include: Reaction vessel (1); The stirring mechanism includes a stirring motor (21) and a stirring paddle (22). One end of the stirring paddle (22) extends into the reaction vessel (1), and the other end is connected to the stirring motor (21) located above the reaction vessel (1). A vortex diffuser, located at the bottom of the reaction vessel (1), includes a turbine (31), a porous filter (32), and an umbrella-shaped diffuser head (33). Interface (5) is connected to the eddy current diffuser.

2. The apparatus according to claim 1, characterized in that, The reaction vessel (1) is equipped with a material inlet.

3. The apparatus according to claim 1, characterized in that, The stirring paddle (22) is one or a combination of blade type, anchor type or spiral type.

4. The apparatus according to claim 1, characterized in that, The turbine (31) has 4-8 blades.

5. The apparatus according to claim 1, characterized in that, The tilt angle of the umbrella-shaped diffuser head (33) is 30°-60°.

6. The apparatus according to claim 1, characterized in that, The device also includes a check valve (4).

7. The apparatus according to claim 1, characterized in that, The device also includes a peristaltic pump.

8. The apparatus according to claim 1, characterized in that, The interface (5) is a detachable structure.

9. The apparatus according to claim 1, characterized in that, The diameter of the umbrella-shaped diffuser head (33) on the side near the porous filter (32) is greater than or equal to the diameter of the porous filter (32).

10. A system for preparing nano-titanium dioxide, characterized in that, The system includes the apparatus for preparing titanate gel according to any one of claims 1-9.

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