A nano zirconium oxide powder preparation device

Abstract

The utility model discloses a kind of nano zirconium oxide powder preparation devices, belong to nanometer material preparation technical field, to solve the problem of uneven liquid phase mixing of reactant in wet chemical precipitation, leading to product particle size distribution wide, easy to agglomerate. The device includes reaction kettle and two sets of independent double-fluid conveying atomization system arranged in the reaction kettle. The first set of system includes first feeding main pipe, first gas feeding main pipe, multiple branch pipes, pipeline and multiple first spray nozzles fixed in the inner wall of the reaction kettle, for atomizing zirconium source solution into aerosol;The second set of system structure corresponds to the first set, for atomizing precipitant solution into aerosol. The utility model is by the cross-collision reaction of reactant after atomizing respectively in gas phase space, accurately control microcosmic reaction environment, effectively inhibit the hard agglomeration of particle, and the obtained nano zirconium oxide powder particle size distribution is narrow, uniform and has good dispersibility.

Description

Technical Field

[0001] This utility model relates to the field of nanomaterial preparation technology, and in particular to a device for preparing nano-zirconia powder. Background Technology

[0002] Nano-zirconia, as an important high-performance ceramic material, shows broad application prospects in structural ceramics, functional ceramics, catalyst supports, and biomedicine due to its excellent mechanical, thermal, electrical, and optical properties. The properties of the powder, especially the particle size, morphology, and dispersibility, directly determine the performance of the final product.

[0003] Among the many methods for preparing nano-zirconia, the wet chemical precipitation method has attracted much attention due to its simple process, low cost, and ease of large-scale production. This method typically involves mixing a solution containing a zirconium source with a precipitant solution in a reaction vessel, controlling the reaction conditions to achieve a supersaturated state of the solute, thereby precipitating nanoscale precursor precipitates.

[0004] However, traditional wet chemical precipitation processes have inherent drawbacks in practice. The core issue is that the reactants are mixed in a macroscopic liquid phase. For example, when the precipitant solution is added dropwise or poured into a zirconium source solution, even under vigorous stirring, a locally extremely high concentration region inevitably forms instantaneously at the interface between the precipitant and the zirconium source solution.

[0005] This localized concentration inhomogeneity leads to highly uneven reaction rates throughout the reactor. In high-concentration areas, nucleation occurs at an extremely rapid rate, resulting in explosive nucleation; while in low-concentration areas, particle growth dominates. This uncontrollable reaction process directly results in a wide particle size distribution and inconsistent morphology in the final product. More seriously, the large number of nanoparticles rapidly generated in high-concentration areas are prone to collision and aggregation in the liquid phase, forming hard agglomerates that are difficult to disperse. This significantly affects subsequent processing and the application performance of the final powder.

[0006] Therefore, this invention proposes a nano-zirconia powder preparation device to address the shortcomings of existing technologies. Utility Model Content

[0007] To overcome the above shortcomings, this utility model provides a nano-zirconia powder preparation device, which aims to improve the existing wet chemical precipitation process for preparing nano-powders. In this process, the macroscopic mixing of reactants in the liquid phase leads to uneven local concentrations and the reaction rate is difficult to control, resulting in a wide product particle size distribution, inconsistent morphology, and a tendency for severe hard agglomeration between particles.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: a nano-zirconia powder preparation device, including a reaction vessel; and further including a first feeding main pipe, a first gas supply main pipe, multiple first feeding branch pipes, multiple first gas supply branch pipes, multiple first pipes, multiple second pipes, multiple first spray nozzles, a second feeding main pipe, a second gas supply main pipe, multiple second feeding branch pipes, multiple second gas supply branch pipes, multiple third pipes, multiple fourth pipes, and multiple second spray nozzles.

[0009] The first feed main and the first gas supply main are both horizontally arranged in the central area inside the reactor. The plurality of first feed branch pipes are radially connected to the upper end of the first feed main, and the plurality of first gas supply branch pipes are radially connected to the upper end of the first gas supply main. The beginning of each first pipe is connected to the end of the first feed branch pipe, and the beginning of each second pipe is connected to the end of a first gas supply branch pipe. The first pipes and the second pipes are arranged side by side in a one-to-one correspondence. Each first spray nozzle is fixedly connected to the inner wall of the reactor and is simultaneously connected to the end of a first pipe and the end of a second pipe.

[0010] Furthermore, both the second feed main and the second gas supply main are horizontally arranged in the central area inside the reactor. The plurality of second feed branch pipes are radially connected to the upper end of the second feed main, and the plurality of second gas supply branch pipes are radially connected to the upper end of the second gas supply main. The beginning of each third pipe is connected to the end of a second feed branch pipe, and the beginning of each fourth pipe is connected to the end of a second gas supply branch pipe. The third pipes and the fourth pipes are arranged side by side in a one-to-one correspondence. Each second spray nozzle is fixedly connected to the inner wall of the reactor and is simultaneously connected to the end of a third pipe and the end of a fourth pipe.

[0011] The first and second spray nozzles are combined on the inner wall of the reactor in a spiral or staggered arrangement to ensure that the different material aerosols sprayed from the two sets of nozzles can be fully cross-mixed in the gas phase space.

[0012] Preferably, the reactor also includes a motor and a stirring paddle; the motor is mounted on the top of the reactor, and the stirring paddle is located at the bottom of the reactor, with the output shaft of the motor connected to the stirring paddle. This structure is used to agitate the product at the bottom of the reactor, preventing it from settling and agglomerating, and ensuring that the product remains in good suspension in the solution.

[0013] Preferably, the inlet ends of both the first and second feed manifolds extend close to the center region of the agitator. This design allows any droplets that may not be fully atomized to be rapidly entrained into the high-speed shear flow field generated by the agitator, thereby being forcibly dispersed and preventing the formation of localized high-concentration areas at the bottom of the vessel.

[0014] Preferably, the first feed main pipe and the first air supply main pipe are coaxially sleeved, and the second feed main pipe and the second air supply main pipe are coaxially sleeved. This pipe-in-pipe structure design is compact, which helps to simplify the internal pipeline layout of the device, saves space, and can play a certain role in preheating or precooling the internal fluid.

[0015] Preferably, as an alternative, the first feed manifold and the second feed manifold are arranged side by side along the central axis of the reactor. This side-by-side arrangement provides a clear structure and facilitates independent installation, inspection, and maintenance of the different manifolds.

[0016] Preferably, it also includes a liquid tank, which is connected to the inlet end of the first feed main pipe via a pipeline, for storing and stably supplying zirconium-containing source solution.

[0017] Preferably, it also includes a precipitant tank, which is connected to the inlet end of the second feed main pipe via a pipeline, for storing and stably supplying the precipitant solution.

[0018] Preferably, the system also includes an atomizer, which is connected to the inlet of the first gas supply main pipe and the inlet of the second gas supply main pipe via pipelines, respectively, to provide high-pressure gas with stable pressure and controllable flow for the two independent atomization systems.

[0019] This utility model has the following beneficial effects: 1. This utility model solves the problems of uneven local concentration and difficult reaction rate control caused by the mixing of reactants in the liquid phase in the prior art by setting up two independent conveying and atomizing systems to atomize the zirconium source solution and precipitant solution into aerosols, and then allowing them to cross-collide and react in the gas phase space of the reactor. This achieves the technical effect of precisely controlling the micro-reaction environment and thus preparing nano-zirconia powder with narrow particle size distribution and uniform morphology.

[0020] 2. This utility model transforms the reaction process from traditional macroscopic mixing in the liquid phase to gas-phase reaction between aerosol droplets, allowing particle nucleation and growth to occur in a relatively independent microenvironment. This solves the problem of severe hard agglomeration of particles during the nucleation and growth stages in the prior art, achieving the technical effect of inhibiting particle agglomeration from the source and significantly improving the dispersibility of the final product. Attached Figure Description

[0021] Figure 1 This is a perspective view of a nano-zirconia powder preparation device proposed in this utility model; Figure 2 This is a schematic diagram of the interior of the reactor of a nano-zirconia powder preparation device proposed in this utility model; Figure 3 This is a schematic diagram of the first pipeline of a nano-zirconia powder preparation device proposed in this utility model; Figure 4 for Figure 3 A magnified structural diagram at point A in the diagram.

[0022] Legend: 1. Reactor; 2. Atomizer; 3. Precipitator tank; 4. Feed tank; 5. Motor; 6. Agitator; 7. First pipe; 8. Second pipe; 9. First spray nozzle; 10. First feeding branch pipe; 11. First air supply branch pipe; 12. First air supply main pipe; 13. First feeding main pipe; 14. Second feeding branch pipe; 15. Second air supply branch pipe; 16. Second air supply main pipe; 17. Third pipe; 18. Fourth pipe; 19. Second spray nozzle; 20. Second feeding main pipe. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Reference Figures 1-4 This utility model provides one embodiment: a nano-zirconia powder preparation device, including a reaction vessel 1. The reaction vessel 1 serves as the reaction body and container of the entire device, used to carry the reaction process and collect the products. The core structure of the device consists of two completely independent dual-fluid delivery atomization systems installed inside the reaction vessel 1.

[0025] The first conveying and atomizing system is used to convey and atomize the zirconium-containing source solution. It includes a first feed main pipe 13 and a first gas supply main pipe 12, both of which are horizontally arranged in the central area inside the reactor 1. Multiple first feed branch pipes 10 are radially connected to the upper end of the first feed main pipe 13 to divert the zirconium-containing source solution from the first feed main pipe 13. Multiple first gas supply branch pipes 11 are radially connected to the upper end of the first gas supply main pipe 12 to divert high-pressure gas from the first gas supply main pipe 12.

[0026] The system also includes multiple first pipes 7 and multiple second pipes 8. The beginning of each first pipe 7 is connected to the end of a first feed branch pipe 10 for conveying the diverted zirconium-containing source solution. The beginning of each second pipe 8 is connected to the end of a first gas supply branch pipe 11 for conveying the diverted high-pressure gas. Each first pipe 7 and its corresponding second pipe 8 are arranged side by side in a one-to-one correspondence, extending together to the inner wall of the reactor 1.

[0027] The system also includes multiple first spray nozzles 9, each of which is fixedly connected to the inner wall of the reactor 1 by welding or threading, and is simultaneously connected to the end of a first pipe 7 and the end of a second pipe 8. The first spray nozzles 9 are used to mix the zirconium-containing source solution from the first pipe 7 with the high-pressure gas from the second pipe 8 to form a zirconium-containing source aerosol.

[0028] The second conveying and atomizing system is used to convey and atomize the precipitant solution. Its structure corresponds to and is completely independent of the first system. It includes a second feed main 20 and a second gas main 16, both horizontally positioned in the central area inside the reactor 1. Multiple second feed branch pipes 14 are radially connected to the upper end of the second feed main 20 to divert the precipitant solution from the second feed main 20. Multiple second gas branch pipes 15 are radially connected to the upper end of the second gas main 16 to divert high-pressure gas from the second gas main 16.

[0029] The system also includes multiple third pipes 17 and multiple fourth pipes 18. The beginning of each third pipe 17 is connected to the end of a second feed branch pipe 14 for conveying the diverted precipitant solution. The beginning of each fourth pipe 18 is connected to the end of a second gas supply branch pipe 15 for conveying the diverted high-pressure gas. Each third pipe 17 and its corresponding fourth pipe 18 are arranged side by side in a one-to-one correspondence, extending together to the inner wall of the reactor 1.

[0030] The system also includes multiple second spray nozzles 19, each of which is fixedly connected to the inner wall of the reactor 1 by welding or threading, and is simultaneously connected to the end of a third pipe 17 and the end of a fourth pipe 18. The second spray nozzles 19 are used to mix the precipitant solution from the third pipe 17 with the high-pressure gas from the fourth pipe 18 to form a precipitant aerosol.

[0031] In order to achieve efficient collision and mixing of the two aerosols in the gas phase space inside the reactor 1, all the first spray nozzles 9 and all the second spray nozzles 19 are arranged in a spiral or staggered manner on the inner wall of the reactor 1. This spatial layout ensures that the cloud of tiny droplets sprayed from different nozzles can form a three-dimensional intersection, thereby achieving uniform mixing on a macro scale and promoting full reaction between particles on a micro scale. The stirring assembly includes a motor 5 and a stirring paddle 6. The motor 5 is fixedly mounted to the top of the reactor 1 by bolts or a bracket. Its output shaft extends vertically downward through a sealed bearing and is connected to the stirring paddle 6 to provide rotational power for the stirring paddle 6. The stirring paddle 6 is located in the bottom space of the reactor 1. Its function is to continuously stir the liquid phase or solid-liquid mixture at the bottom of the reactor during or after the reaction to prevent the generated nano-zirconia particles from settling, caking, and hard agglomerating, ensuring that the product maintains a good suspension and dispersion state in the solution.

[0032] In a preferred embodiment, the inlet ends of both the first feed manifold 13 and the second feed manifold 20 extend downwards, with their outlets close to the central region of the agitator 6. This structural layout ensures that even if a small amount of incompletely atomized droplets or reactants fall directly, they will be quickly drawn into the high-speed shear flow field generated by the agitator 6, thereby being forcibly dispersed and mixed. This avoids the formation of localized high-concentration areas at the bottom of the vessel, further improving the uniformity of the reaction.

[0033] There are several implementation methods for the specific layout of the internal piping system. In one implementation, the first feeding main pipe 13 and the first air supply main pipe 12 are coaxially fitted together to form a pipe-in-pipe structure; similarly, the second feeding main pipe 20 and the second air supply main pipe 16 are also coaxially fitted together. This coaxially fitted structure is compact and helps to simplify the internal piping layout.

[0034] In another embodiment, the first feed main 13 and the second feed main 20 are arranged side by side along the central axis of the reactor 1, and the first gas supply main 12 and the second gas supply main 16 are also arranged side by side accordingly. This side-by-side arrangement facilitates the independent installation and maintenance of different pipelines; In a preferred embodiment, in order to achieve a stable supply of zirconium source solution, the device also includes a feed tank 4, which is connected to the feed end of the first feed main pipe 13 via a pipeline.

[0035] In a preferred embodiment, in order to achieve a stable supply of precipitant solution, the device also includes a precipitant tank 3, which is connected to the feed end of the second feed main pipe 20 via a pipeline.

[0036] In a preferred embodiment, in order to provide the high-pressure gas required for atomization, the device further includes an atomizer 2, which is connected to the air inlet of the first air supply manifold 12 and the air inlet of the second air supply manifold 16 via pipelines.

[0037] In a preferred embodiment, to make the internal pipeline structure more compact, the first feeding main pipe 13 and the first air supply main pipe 12 are coaxially sleeved, and the second feeding main pipe 20 and the second air supply main pipe 16 are coaxially sleeved, forming two independent pipe-in-pipe structures.

[0038] As an alternative preferred embodiment, in order to facilitate independent installation and maintenance of the pipelines, the first feed main pipe 13 and the second feed main pipe 20 are arranged side by side along the central axis of the reactor 1.

[0039] In a preferred embodiment, in order to quickly disperse any unatomized droplets that may exist, the feed ends of the first feed manifold 13 and the second feed manifold 20 both extend downwards, with their outlet positions close to the center area of ​​the agitator 6.

[0040] Working principle: First, start the motor 5 installed on the top of the reactor 1. The motor 5 then drives the stirring paddle 6 connected to it to start rotating continuously in the liquid phase area at the bottom of the reactor 1 to maintain the suspension of the product at the bottom of the reactor and ensure uniform mixing. At the same time, the preparation process is officially started. The zirconium source mixed solution contained in the liquid tank 4 is transported to the first feed main pipe 13 located in the center of the reactor 1 and close to the center of the agitator 6. After the zirconium source mixed solution rises along the first feed main pipe 13, it is diverted through the first feed branch pipes 10 which are distributed radially to the first pipe 7 fixed to the inner wall of the reactor 1, and finally reaches the first spray nozzle 9. Simultaneously, the atomizer 2 on the side close to the liquid tank 4 is started to generate high-pressure gas. The high-pressure gas is transported to the first gas supply main pipe 12 at the center, and then diverted through the first gas supply branch pipes 11 which are arranged radially to the second pipe 8 which is arranged parallel to the first pipe 7, and finally reaches the first spray nozzle 9 as well. On the other hand, the precipitant solution contained in the precipitant tank 3 is transported to the second feed main pipe 20 located in the center of the reactor 1 and close to the axis of the agitator 6. After the solution rises along the second feed main pipe 20, it is diverted through the radially distributed second feed branch pipes 14 to the third pipe 17 fixed to the inner wall of the reactor 1, and finally reaches the second spray nozzle 19. The atomizer 2 near the precipitant tank 3 generates high-pressure gas, which is transported to the central second air supply main pipe 16, and diverted through the radially distributed second air supply branch pipes 15 into the fourth pipe 18 arranged parallel to the third pipe 17, and finally reaches the second spray nozzle 19 as well. When the liquid and gas components converge at the terminal nozzles, a two-fluid atomization process occurs inside the reactor 1. At the first spray nozzle 9, high-pressure, high-speed gas from the second pipe 8 exerts strong shearing and impact on the zirconium-containing source solution from the first pipe 7, instantly breaking it down and dispersing it into micron- or nano-sized zirconium-containing aerosols. Simultaneously, at the second spray nozzle 19, high-pressure gas from the fourth pipe 18 uses the same shearing principle to break down the precipitant solution from the third pipe 17 into extremely fine precipitant aerosols. Because the first spray nozzle 9 and the second spray nozzle 19 are arranged in a specific spiral or staggered pattern on the upper part of the inner wall of the reactor 1, the two types of aerosols generate sufficient cross-contact and collision in the gas phase space above the stirring paddle 6, resulting in a highly efficient sol-coprecipitation reaction. The precipitate products generated by the reaction are uniformly and independently nucleated, and then naturally settle to the bottom of the reactor 1 under gravity. Finally, they are thoroughly stirred and mixed by the continuously rotating stirring paddle 6 at the bottom, completing the preparation of nano-zirconia powder.

Claims

1. A device for preparing nano-zirconia powder, comprising a reaction vessel (1), characterized in that, Also includes: The first feed main pipe (13) and the first gas supply main pipe (12) are both horizontally arranged in the central area inside the reactor (1); Multiple first feeding branches (10) are radially connected to the upper end of the first feeding main pipe (13), and multiple first air supply branches (11) are radially connected to the upper end of the first air supply main pipe (12). Multiple first pipes (7) and multiple second pipes (8), the beginning of each first pipe (7) is connected to the end of a first feeding branch pipe (10), the beginning of each second pipe (8) is connected to the end of a first air supply branch pipe (11), and the first pipes (7) and the second pipes (8) are arranged side by side in a one-to-one correspondence. Multiple first spray nozzles (9), each first spray nozzle (9) is fixedly connected to the inner wall of the reactor (1) and simultaneously connected to the end of a first pipe (7) and the end of a second pipe (8); The second feed main pipe (20) and the second gas supply main pipe (16) are both horizontally arranged in the central area inside the reactor (1); Multiple second feeding branches (14) are radially connected to the upper end of the second feeding main pipe (20), and multiple second air supply branches (15) are radially connected to the upper end of the second air supply main pipe (16). Multiple third pipes (17) and multiple fourth pipes (18), the beginning of each third pipe (17) is connected to the end of a second feeding branch pipe (14), the beginning of each fourth pipe (18) is connected to the end of a second air supply branch pipe (15), and the third pipes (17) and the fourth pipes (18) are arranged side by side in a one-to-one correspondence. And a plurality of second spray nozzles (19), each of the second spray nozzles (19) being fixedly connected to the inner wall of the reactor (1) and simultaneously connected to the end of a third pipe (17) and the end of a fourth pipe (18); The first spray nozzle (9) and the second spray nozzle (19) are arranged in a spiral or staggered manner on the inner wall of the reactor (1).

2. The nano-zirconia powder preparation apparatus according to claim 1, characterized in that, The device also includes a motor (5) and a stirring paddle (6); the motor (5) is installed on the top of the reactor (1), the stirring paddle (6) is located at the bottom of the reactor (1), and the output shaft of the motor (5) is connected to the stirring paddle (6) in a transmission connection.

3. The nano-zirconia powder preparation apparatus according to claim 2, characterized in that, The feed end of the first feed manifold (13) and the feed end of the second feed manifold (20) both extend to the central region close to the agitator (6).

4. The nano-zirconia powder preparation apparatus according to claim 1, characterized in that, The first feeding main pipe (13) is coaxially sleeved with the first air supply main pipe (12), and the second feeding main pipe (20) is coaxially sleeved with the second air supply main pipe (16).

5. The nano-zirconia powder preparation apparatus according to claim 1 or 4, characterized in that, The first feed main pipe (13) and the second feed main pipe (20) are arranged side by side along the central axis of the reactor (1).

6. The nano-zirconia powder preparation apparatus according to claim 1, characterized in that, The device also includes a liquid tank (4), which is connected to the feed end of the first feeding main pipe (13) via a pipeline.

7. The nano-zirconia powder preparation apparatus according to claim 1, characterized in that, The device also includes a precipitant tank (3), which is connected to the feed end of the second feed main pipe (20) via a pipeline.

8. The nano-zirconia powder preparation apparatus according to claim 1, characterized in that, The device also includes an atomizer (2), which is connected to the air inlet of the first air supply main pipe (12) and the air inlet of the second air supply main pipe (16) through pipelines.

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