Piezoelectric powder continuous production device and preparation method

Abstract

This invention relates to a continuous production apparatus for piezoelectric powders, comprising an installation cylinder, a liquid supply pump, a reactor, an atomizing nozzle, a three-way valve, a spray filtration assembly, and a sealed feeding assembly. The sealed feeding assembly includes a sealing shell, a rotating sealing plate, a feed inlet, a discharge outlet, a cooling chamber, a coolant inlet and outlet, a rotary joint, a drive assembly, and a discharge pipe. The rotating sealing plate divides the inner cavity of the sealing shell into multiple independent chambers, with the feed inlet directly opposite only one chamber, and the discharge outlet staggered from the feed inlet. The drive assembly drives the rotating sealing plate to rotate continuously, achieving uninterrupted discharge of materials while the reactor is sealed. Coolant enters the cooling chamber through the rotary joint, simultaneously cooling the high-temperature powder to below 100°C to prevent secondary sintering. Exhaust gas is purified by the spray filtration assembly before being discharged. This invention achieves continuous production of piezoelectric powders, offering advantages such as reliable sealing, uniform cooling, high product sphericity, and good batch consistency, and is suitable for the industrial production of various piezoelectric powders.

Description

Technical Field

[0001] This invention relates to the field of piezoelectric powder production, and specifically to a continuous piezoelectric powder production apparatus and preparation method. Background Technology

[0002] Piezoelectric powders (such as barium titanate and sodium bismuth titanate) possess high dielectric constants, low dielectric losses, and excellent piezoelectric properties, making them a core material for fabricating electronic components such as multilayer ceramic capacitors (MLCCs), thermistors (PTCRs), and piezoelectric sensors. As electronic devices evolve towards miniaturization and high performance, increasingly stringent requirements are being placed on the particle size uniformity, sphericity, dispersibility, and batch stability of piezoelectric powders.

[0003] Currently, the main methods for preparing piezoelectric powders include solid-state methods, co-precipitation methods, hydrothermal methods, and spray pyrolysis methods. Among these, spray pyrolysis methods have attracted widespread attention due to their rapid process, uniform composition, and ability to produce spherical particles.

[0004] Chinese patent CN101857436B discloses a method for preparing a type of potassium sodium niobate-based lead-free piezoelectric ceramic powder. This method employs liquid-phase coating combined with spray drying technology to coat soluble components onto the surface of insoluble particles, followed by calcination to obtain powder-50. While this method achieves uniform dispersion of the components, its spray drying process is only used for mixing and drying, not for high-temperature thermal decomposition reactions. Furthermore, it does not address the cooling and collection of the powder after high-temperature calcination, thus failing to achieve continuous production from raw materials to finished products.

[0005] Chinese patent application CN120646900A discloses a method for producing spherical barium titanate powder. The method involves atomizing a precursor solution and spraying it into a high-temperature reactor for flame melting and crystallization, followed by gradient cooling and spherical solidification. Finally, the powder is collected in stages using a cyclone separator and a bag filter. While this method improves the powder morphology, it has the following shortcomings in practical applications: First, the bottom of the reactor is only connected to the collection system through the discharge port, without a sealed discharge structure. During continuous discharge, the protective atmosphere inside the reactor is prone to leakage, leading to unstable crystal structure. Second, the powder temperature after thermal decomposition reaches 180-220℃. If it is not cooled in time during collection, the powder particles are prone to secondary sintering, forming hard agglomerates and destroying the spherical morphology. Third, the method does not address tail gas purification; direct emission of the acidic gases generated during the reaction will cause environmental pollution.

[0006] Chinese patent CN103626223B discloses a process for producing barium titanate, which involves deep hydrolysis of titanium tetrachloride to obtain metatitanic acid, mixing it with barium hydroxide solution, and then feeding it into an ultrasonic sprayer for ultrasonic spray thermal decomposition. Finally, it is calcined to obtain tetragonal phase barium titanate. However, this patent also fails to address the issues of continuous sealed discharge from the bottom of the reactor and simultaneous cooling of the high-temperature powder. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art by providing a continuous production apparatus and preparation method for piezoelectric powder.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: a continuous production apparatus and preparation method for piezoelectric powder, comprising an installation cylinder, a liquid supply pump disposed on one side of the installation cylinder, a reaction furnace disposed in the upper part of the installation cylinder, a heating element disposed in the reaction furnace, an atomizing nozzle disposed at the top of the reaction furnace, a three-way valve disposed on the liquid inlet of the atomizing nozzle with one inlet connected to an external gas supply device and the other inlet connected to the liquid supply pump, a spray filter assembly for filtering exhaust gas and connected to the reaction furnace inside the installation cylinder, and a sealing and feeding assembly disposed in the middle of the installation cylinder and located below the reaction furnace; the sealing and feeding assembly includes: a seal fixed inside the installation cylinder. The system comprises: a shell; a rotating sealing plate rotatably disposed within the sealing shell, dividing the inner cavity of the sealing shell into multiple independent chambers circumferentially; a feed inlet located at the top of the sealing shell and connected to the reactor feed port; a discharge port located at the bottom of the sealing shell; a cooling chamber located inside the rotating sealing plate; a coolant inlet and a coolant outlet located on the top and bottom surfaces of the rotating sealing plate and connected to the cooling chamber, respectively; a rotary joint installed at the coolant inlet and coolant outlet and connected to external coolant equipment, respectively; a drive assembly located at the bottom of the sealing shell for driving the rotating sealing plate to rotate continuously; and a discharge pipe located at the bottom of the mounting cylinder; wherein the feed inlet is directly opposite only one of the chambers.

[0009] Preferably, the rotating sealing plate is a cross-shaped sealing plate, which divides the inner cavity of the sealing shell into four chambers with an included angle of 90° between adjacent chambers, and the inlet and outlet are offset by 180° in the circumferential direction.

[0010] Preferably, the rotating sealing plate is welded from a left half shell and a right half shell, and a cooling chamber is formed inside it; at least one flow guide baffle is provided in the cooling chamber to guide the coolant to flow along a predetermined path, so that the coolant flows through each blade area.

[0011] Preferably, the blade edge of the rotary sealing plate is provided with an elastic sealing strip; the sealing strip is made of polytetrafluoroethylene filled with carbon fiber.

[0012] Preferably, the drive assembly includes a driven gear sleeved on the outer wall of the coolant outlet and a drive motor installed at the bottom of the sealed housing, and the output end of the drive motor is provided with a driving gear that meshes with the driven gear.

[0013] Preferably, the spray filtration assembly includes a spray housing, a drain pipe disposed on one side of the bottom of the spray housing, an air inlet pipe disposed on the side wall of the spray housing and above the drain pipe and communicating with the reactor, a plurality of packing layers disposed at intervals inside the spray housing and above the air inlet pipe, and a plurality of spray pipes disposed inside the spray housing and respectively located directly above each packing layer.

[0014] Preferably, the liquid supply pump is a peristaltic pump; and the atomizing nozzle is a dual-fluid atomizing nozzle.

[0015] Preferably, the reactor is provided with multiple baffles at an angle.

[0016] Preferably, the heating element is a silicon carbide infrared radiation tube.

[0017] A method for continuous production of piezoelectric powder includes the following steps:

[0018] S1. Prepare the precursor solution;

[0019] S2. The liquid supply pump and the external gas supply equipment continuously deliver the precursor liquid and the gas at a certain flow rate to the atomizing nozzle, respectively, and atomize the precursor liquid into micron-sized droplets and continuously spray it into the reaction furnace.

[0020] S3. The high temperature inside the reactor causes the droplets to thermally decompose and continuously generate solid powder;

[0021] S4. At high temperatures, solid powder crystallizes into piezoelectric powder;

[0022] S5. Piezoelectric powder continuously falls into the feed port and enters a chamber of the rotary sealing plate. The drive mechanism drives the rotary sealing plate to rotate continuously. The chamber containing the powder rotates to the discharge port and is discharged. At the same time, coolant continuously enters the cooling chamber through the rotary joint to cool the rotary sealing plate and the powder.

[0023] S6. The discharged piezoelectric powder is continuously collected through the discharge pipe;

[0024] S7. The exhaust gas enters the spray casing through the intake pipe for purification before being discharged.

[0025] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0026] 1. Continuous sealed discharge: The rotating sealing plate and the continuously rotating chamber structure enable uninterrupted discharge. The partitions of at least two chambers are always in a sealed position, effectively preventing the leakage of reactive gases and ensuring crystal stability.

[0027] 2. Synchronous cooling and anti-sintering: The rotating sealing plate integrates a cooling chamber, and the rotating joint realizes the dynamic and static sealing conversion. During the discharge process, the powder is directly cooled, which completely avoids secondary sintering and maintains the spherical morphology.

[0028] 3. Exhaust gas environmental protection treatment: A multi-stage packed spray alkaline absorption system is adopted to efficiently remove HCl, NOx and CO2, meeting environmental emission requirements;

[0029] 4. Compact structure and easy automation: The device has a high degree of integration. The speed of the drive motor, the flow rate of the coolant, the pH of the spray liquid, etc. can all be controlled in a closed loop by the PLC, which is suitable for industrial continuous production. Attached Figure Description

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings:

[0031] Appendix Figure 1 This is a cross-sectional schematic diagram of the piezoelectric powder continuous production apparatus and preparation method described in this invention;

[0032] Appendix Figure 2 This is a cross-sectional schematic diagram of the sealed feeding component of the piezoelectric powder continuous production apparatus and preparation method according to the present invention;

[0033] Appendix Figure 3 This is a top view of the internal structure of the sealed feeding assembly of the piezoelectric powder continuous production device and preparation method described in this invention.

[0034] The components include: 1. Mounting cylinder; 2. Liquid supply pump; 3. Reactor; 4. Heating element; 5. Atomizing nozzle; 6. Spray filter assembly; 61. Spray shell; 62. Drain pipe; 63. Air inlet pipe; 64. Packing layer; 65. Spray pipe; 7. Sealing and feeding assembly; 71. Sealing shell; 72. Rotary sealing plate; 73. Feed inlet; 74. Discharge outlet; 75. Cooling chamber; 76. Coolant inlet; 77. Coolant outlet; 78. Rotary joint; 79. Drive assembly; 791. Drive motor; 792. Drive gear; 793. Driven gear; 8. Flow guide baffle; 9. Elastic sealing strip; 10. Baffle. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0036] Appendix Figure 1-3The piezoelectric powder continuous production apparatus and preparation method of the present invention includes an installation cylinder 1, a liquid supply pump 2 disposed on one side of the installation cylinder 1, a reaction furnace 3 disposed in the upper part of the installation cylinder 1, a heating element 4 disposed in the reaction furnace 3, an atomizing nozzle 5 disposed on the top of the reaction furnace 3, a three-way valve disposed on the liquid inlet of the atomizing nozzle 5 with one inlet connected to an external air supply device and the other inlet connected to the liquid supply pump 2, a spray filter assembly 6 disposed on the installation cylinder 1 and connected to the reaction furnace 3 inside the installation cylinder 1 for filtering exhaust gas, and a component disposed on the installation cylinder 1. The sealing and feeding assembly 7 is located in the center of the inner part of the reactor 3 and below it. The sealing and feeding assembly 7 includes: a sealing shell 71 fixed in the mounting cylinder 1; a rotating sealing plate 72 rotatably disposed in the sealing shell 71 and dividing the inner cavity of the sealing shell 71 into multiple independent chambers circumferentially; a feed inlet 73 disposed at the top of the sealing shell 71 and communicating with the feed port of the reactor 3; a discharge port 74 disposed at the bottom of the sealing shell 71; a cooling chamber 75 disposed inside the rotating sealing plate 72; and a cooling chamber 75 disposed on the middle of the top and bottom surfaces of the rotating sealing plate 72 and communicating with the reactor 3. The cooling chamber 75 includes a coolant inlet 76 and a coolant outlet 77 connected to it; a rotary joint 78 installed on the coolant inlet 76 and the coolant outlet 77 respectively and connected to an external coolant device; a drive assembly 79 located at the bottom of the sealing shell 71 for driving the rotary sealing plate 72 to rotate continuously; and a discharge pipe located at the bottom of the mounting cylinder 1. The inlet 73 is directly opposite only one of the chambers. The drive assembly 79 includes a driven gear 793 sleeved on the outer wall of the coolant outlet 77 and a drive gear installed at the bottom of the sealing shell 71. The motor 791 has a drive gear 792 at its output end that meshes with the driven gear 793. The spray filtration assembly 6 includes a spray housing 61, a drain pipe 62 located on one side of the bottom of the spray housing, an air inlet pipe 63 located on the side wall of the spray housing 61 and above the drain pipe 62, communicating with the reactor 3, multiple packing layers 64 spaced apart within the spray housing 61 and above the air inlet pipe 63, and multiple spray pipes 65 located within the spray housing 61 and directly above each packing layer 64.

[0037] Furthermore, the rotating sealing plate 72 is a cross-shaped sealing plate, which divides the inner cavity of the sealing shell 71 into four chambers with an included angle of 90° between adjacent chambers. The inlet 73 and the outlet 74 are offset by 180° in the circumferential direction, ensuring that at least two chambers are always in a sealed state, realizing continuous discharge under dynamic sealing and preventing leakage of the reaction atmosphere.

[0038] Furthermore, the rotating sealing plate 72 is welded from the left half shell and the right half shell, and a cooling cavity 75 is formed inside it; the cooling cavity 75 is provided with at least one flow guide baffle 8, which is used to guide the coolant to flow along a predetermined path, so that the coolant flows through each blade area, which simplifies the manufacturing process and guides the coolant to flow evenly through each blade area, avoids cooling dead corners, and ensures that the rotating sealing plate has a uniform temperature and efficient cooling.

[0039] Furthermore, the blade edge of the rotary sealing plate 72 is provided with an elastic sealing strip 9; the sealing strip is made of polytetrafluoroethylene and carbon fiber, which can dynamically compensate for thermal expansion and wear gaps, and achieve long-term stable airtight sealing.

[0040] Furthermore, the liquid supply pump 2 is a peristaltic pump; the atomizing nozzle 5 is a dual-fluid atomizing nozzle 5, which realizes precise liquid supply without pulsation or pollution, and in conjunction with the dual-fluid atomizing nozzle, obtains micron-sized droplets with uniform particle size, ensuring the consistency and sphericity of thermal decomposition products.

[0041] Furthermore, multiple baffles 10 are inclinedly arranged inside the reactor 3 to extend the movement path and residence time of the powder in the furnace, ensuring that thermal decomposition and crystallization are fully carried out, and improving the purity and crystal phase integrity of the product.

[0042] Furthermore, the heating element 4 is a silicon carbide infrared radiation tube, which is resistant to high temperature, has a fast thermal response, and high radiation efficiency. It can achieve precise temperature control over a wide temperature range of 400-1000℃, ensuring that the powder is fully pyrolyzed and crystallized.

[0043] A method for continuous production of piezoelectric powder includes the following steps:

[0044] S1. Prepare the precursor solution;

[0045] S2. The liquid supply pump 2 and the external gas supply equipment continuously deliver the precursor liquid and a certain flow rate of gas to the atomizing nozzle 5, respectively, and atomize the precursor liquid into micron-sized droplets and continuously spray it into the reaction furnace 3.

[0046] S3. The high temperature inside reactor 3 thermally decomposes the droplets to continuously generate solid powder;

[0047] S4. At high temperatures, solid powder crystallizes into piezoelectric powder;

[0048] S5. Piezoelectric powder continuously falls into the feed inlet 73 and enters a chamber of the rotary sealing plate 72. The drive mechanism drives the rotary sealing plate 72 to rotate continuously. The chamber containing the powder rotates to the discharge outlet 74 and is discharged. At the same time, the coolant continuously enters the cooling chamber 75 through the rotary joint 78 to cool the rotary sealing plate 72 and the powder.

[0049] S6. The discharged piezoelectric powder is continuously collected through the discharge pipe;

[0050] S7. The exhaust gas enters the spray housing 61 through the intake pipe 63 for purification, and is then discharged.

[0051] The present invention also provides a method for continuous production of piezoelectric powder, which is prepared by the above-described preparation method.

[0052] The present invention will be described in detail below through embodiments.

[0053] Example 1: Continuous production of barium titanate (BaTiO3) powder

[0054] S1. Weigh 2.53g of barium acetate powder and stir to dissolve it in a mixture of 30ml acetic acid and 15ml methanol.

[0055] S2. Weigh 3.44g of tetrabutyl titanate and stir to dissolve it in 2ml of ethanol;

[0056] S3. Mix the solutions in S1 and S2, and then stir;

[0057] S4. Add 2 ml of acetylacetone and 1 g of PVP powder to the solution in S3, stir thoroughly to dissolve, and obtain the precursor solution;

[0058] The S5.30rpm peristaltic pump and external gas supply equipment continuously deliver the precursor liquid and the gas at a flow rate of 10L / min to the atomizing nozzle 5, atomizing the precursor liquid into micron-sized droplets and continuously spraying it into the reaction furnace 3.

[0059] S6. The high temperature inside reactor 3 causes the droplets to thermally decompose and continuously generate solid powder;

[0060] S7. At a high temperature of 800°C, the solid powder crystallizes into barium titanate nanoparticles;

[0061] S8. Barium titanate nanopowder continuously falls into the feed port 73 and enters a chamber of the rotary sealing plate 72. The drive mechanism drives the rotary sealing plate 72 to rotate continuously. The chamber containing barium titanate nanopowder rotates to the discharge port 74 and is discharged. At the same time, coolant continuously enters the cooling chamber 75 through the rotary joint 78 to cool the rotary sealing plate 72 and the barium titanate nanopowder.

[0062] S9. The discharged barium titanate nanoparticles are continuously collected through the discharge pipe;

[0063] S10. The exhaust gas enters the spray housing 61 through the intake pipe 63 for purification, and is then discharged.

[0064] Example 2: Continuous production of sodium bismuth titanate ((Na0.5Bi0.5)TiO3) powder:

[0065] S1. Weigh 0.78g of bismuth acetate powder and 0.165g of anhydrous sodium acetate powder, and stir to dissolve them in a mixture of 15ml of acetic acid and 15ml of methanol.

[0066] S2. Weigh 1.375g of tetrabutyl titanate and dissolve it in 4ml of ethanol by stirring.

[0067] S3. Mix the solutions in S1 and S2, and then stir;

[0068] S4. Add 1.5g of PVP powder to the solution in S3, stir thoroughly to dissolve, and obtain the precursor solution;

[0069] The S5.200rpm peristaltic pump and external gas supply equipment continuously deliver the precursor liquid and the gas at a flow rate of 50L / min to the atomizing nozzle 5, atomizing the precursor liquid into micron-sized droplets and continuously spraying it into the reaction furnace 3.

[0070] S6. The high temperature inside reactor 3 thermally decomposes the droplets to continuously generate solid powder;

[0071] S7. At a high temperature of 600°C, the solid powder crystallizes into sodium bismuth titanate nanoparticles;

[0072] S8. Bismuth sodium titanate nanopowder continuously falls into the feed port 73 and enters a chamber of the rotary sealing plate 72. The drive mechanism drives the rotary sealing plate 72 to rotate continuously. The chamber containing the bismuth sodium titanate nanopowder rotates to the discharge port 74 and is discharged. At the same time, the coolant continuously enters the cooling chamber 75 through the rotary joint 78 to cool the rotary sealing plate 72 and the bismuth sodium titanate nanopowder.

[0073] S9. The discharged sodium bismuth titanate nanopowder is continuously collected through the discharge pipe;

[0074] S10. The exhaust gas enters the spray housing 61 through the intake pipe 63 for purification, and is then discharged.

[0075] Example 3: Sodium-doped barium titanate (BaO). 95 Na0. 05 Continuous production of TiO3 powder:

[0076] S1. Weigh 2.45g of barium acetate powder and 0.083g of anhydrous sodium acetate powder, and stir to dissolve them in a mixture of 30ml of acetic acid and 15ml of methanol.

[0077] S2. Weigh 3.44g of tetrabutyl titanate and stir to dissolve it in 2ml of ethanol;

[0078] S3. Mix the solutions in S1 and S2, and then stir;

[0079] S4. Add 2 ml of acetylacetone and 1 g of PVP powder to the solution in S3, stir thoroughly to dissolve, and obtain the precursor solution;

[0080] The S5.10rpm peristaltic pump and external gas supply equipment continuously deliver the precursor liquid and the gas with a flow rate of 300L / min to the atomizing nozzle 5, atomizing the precursor liquid into micron-sized droplets and continuously spraying it into the reaction furnace 3.

[0081] S6. The high temperature inside reactor 3 thermally decomposes the droplets to continuously generate solid powder;

[0082] S7. At a high temperature of 750°C, the solid powder crystallizes into sodium-doped barium titanate nanoparticles;

[0083] S8. Sodium-doped barium titanate nanopowder continuously falls into the feed port 73 and enters a chamber of the rotary sealing plate 72. The drive mechanism drives the rotary sealing plate 72 to rotate continuously. The chamber containing sodium-doped barium titanate nanopowder rotates to the discharge port 74 and is discharged. At the same time, coolant continuously enters the cooling chamber 75 through the rotary joint 78 to cool the rotary sealing plate 72 and the sodium-doped barium titanate nanopowder.

[0084] S9. The discharged sodium-doped barium titanate nanoparticles are continuously collected through the discharge pipe;

[0085] S10. The exhaust gas enters the spray housing 61 through the intake pipe 63 for purification, and is then discharged.

[0086] Example 4: Continuous production of strontium-doped barium titanate (Ba0.8Sr0.2TiO3) powder:

[0087] S1. Weigh 2.53g of barium acetate powder and 0.04g of strontium acetate powder, and stir to dissolve them in a mixture of 30ml of acetic acid and 15ml of methanol.

[0088] S2. Weigh 3.44g of tetrabutyl titanate and stir to dissolve it in 2ml of ethanol;

[0089] S3. Mix the solutions in S1 and S2, and then stir;

[0090] S4. Add 2 ml of acetylacetone and 1 g of PVP powder to the solution in S3, stir thoroughly to dissolve, and obtain the precursor solution;

[0091] The S5.800rpm peristaltic pump and external gas supply equipment continuously deliver the precursor liquid and gas at a flow rate of 0.2L / min to the atomizing nozzle 5, atomizing the precursor liquid into micron-sized droplets and continuously spraying it into the reaction furnace 3.

[0092] S6. The high temperature inside reactor 3 thermally decomposes the droplets to continuously generate solid powder;

[0093] S7. At a high temperature of 820°C, the solid powder crystallizes into strontium-doped barium titanate nanoparticles;

[0094] S8. Strontium-doped barium titanate nanopowder continuously falls into the feed inlet 73 and enters a chamber of the rotary sealing plate 72. The drive mechanism drives the rotary sealing plate 72 to rotate continuously, and the chamber containing the strontium-doped barium titanate nanopowder rotates to the discharge outlet 74 for discharge. At the same time, coolant continuously enters the cooling chamber 75 through the rotary joint 78 to cool the rotary sealing plate 72 and the strontium-doped barium titanate nanopowder.

[0095] S9. The discharged strontium-doped barium titanate nanopowder is continuously collected through the discharge pipe;

[0096] S10. The exhaust gas enters the spray housing 61 through the intake pipe 63 for purification, and is then discharged.

[0097] Example 5: Continuous production of strontium-doped barium titanate (Ba0.8Sr0.2TiO3) powder:

[0098] S1. Weigh 2.53g of barium acetate powder and 0.046g of lanthanum acetate powder, and stir to dissolve them in a mixture of 30ml of acetic acid and 15ml of methanol.

[0099] S2. Weigh 3.44g of tetrabutyl titanate and stir to dissolve it in 2ml of ethanol;

[0100] S3. Mix the solutions in S1 and S2, and then stir;

[0101] S4. Add 2 ml of acetylacetone and 1 g of PVP powder to the solution in S3, stir thoroughly to dissolve, and obtain the precursor solution;

[0102] The peristaltic pump with an S5.2 rpm and the external gas supply equipment continuously deliver the precursor liquid and the gas with a flow rate of 500 L / min to the atomizing nozzle 5, atomizing the precursor liquid into micron-sized droplets and continuously spraying it into the reaction furnace 3.

[0103] S6. The high temperature inside reactor 3 thermally decomposes the droplets to continuously generate solid powder;

[0104] S7. At a high temperature of 800°C, the solid powder crystallizes into lanthanum-doped barium titanate nanoparticles;

[0105] S8. Lanthanum-doped barium titanate nanopowder continuously falls into the feed inlet 73 and enters a chamber of the rotary sealing plate 72. The drive mechanism drives the rotary sealing plate 72 to rotate continuously. The chamber containing the lanthanum-doped barium titanate nanopowder rotates to the discharge outlet 74 and is discharged. At the same time, the coolant continuously enters the cooling chamber 75 through the rotary joint 78 to cool the rotary sealing plate 72 and the lanthanum-doped barium titanate nanopowder.

[0106] S9. The discharged lanthanum-doped barium titanate nanopowder is continuously collected through the discharge pipe;

[0107] S10. The exhaust gas enters the spray housing 61 through the intake pipe 63 for purification, and is then discharged.

[0108] In operation: A peristaltic pump continuously delivers the prepared precursor liquid to the dual-fluid atomizing nozzle 5 at a constant flow rate; an external gas supply device delivers gas at a certain flow rate to the dual-fluid atomizing nozzle 5. Inside the nozzle, the high-speed airflow shears and collides with the liquid, breaking the precursor liquid into micron-sized droplets. The atomized gas and liquid two-phase flow is ejected from the nozzle outlet and enters the upper part of the reactor 3. The reactor 3 is heated to the set temperature by a silicon carbide infrared radiation tube. During the downward movement of the atomized droplets inside the reactor 3: the solvent evaporates rapidly, and the solute precipitates to form solid precursor particles; the solid precursor undergoes a thermal decomposition reaction to generate metal oxides or composite oxides; each component undergoes a solid-phase reaction to generate the target piezoelectric crystal phase, while the particles shrink into a spherical shape under the action of surface tension. The baffle 10 on the inner wall of the reactor 3 prolongs the residence time of the powder in the high-temperature zone, ensuring that thermal decomposition and crystallization proceed fully. The piezoelectric powder generated in reactor 3 falls into the sealing shell 71 from the feed inlet 73 by gravity, entering one chamber of the rotating sealing plate 72. After a certain amount is collected, the drive motor 791 drives the rotating sealing plate 72 to rotate via the drive gear 792 and the driven gear 793. The rotating sealing plate 72 divides the inner cavity of the sealing shell 71 into multiple independent chambers. The feed inlet 73 is directly opposite only one of the chambers, and the discharge outlet 74 is offset from the feed inlet 73 by 180° in the circumferential direction. When the rotating sealing plate 72 rotates, each chamber sequentially undergoes the following stages: feeding stage, transfer stage, discharge stage, and idling stage. Since the partitions of at least two chambers are always in a sealed position when the rotating sealing plate 72 rotates, it ensures that the protective atmosphere inside reactor 3 cannot leak out, and outside air cannot enter, achieving continuous discharge under dynamic sealing. The elastic sealing strip 9 on the edge of the rotating sealing plate 72 blades further compensates for mechanical clearances and improves sealing reliability. An external coolant system continuously supplies coolant into the cooling chamber 75 inside the rotating sealing plate 72 via a rotary joint 78. The rotary joint 78 achieves a dynamic seal between the stationary pipeline and the rotating component. The coolant flows within the cooling chamber 75, absorbing heat conducted from the powder to the chamber wall, causing the powder temperature to drop rapidly. The heated coolant flows back to the external cooling system via the rotary joint 78, is cooled by a heat exchanger, and is then recycled. This completely prevents secondary sintering of the high-temperature powder after discharge, maintaining its spherical morphology and high dispersibility. The cooled powder is continuously collected via a discharge pipe. The exhaust gas generated by thermal decomposition in the reactor 3 enters the spray shell 61 via the inlet pipe 63. The exhaust gas passes through multiple packing layers 64 sequentially from bottom to top, coming into countercurrent contact with the alkaline water continuously sprayed from the spray pipe 65, undergoing a neutralization reaction and absorbing acidic gases and CO2 from the exhaust gas. The packing layer 64 increases the gas-liquid contact area, improving absorption efficiency. The purified gas is discharged through the top of the spray shell 61, and the absorbed waste liquid is discharged through the drain pipe 62.

[0109] The above are merely specific application examples of the present invention and do not constitute any limitation on the scope of protection of the present invention. All technical solutions formed by equivalent transformations or substitutions fall within the scope of protection of the present invention.

Claims

1. A continuous production apparatus for piezoelectric powder, characterized in that: The system includes an installation cylinder, a liquid supply pump located on one side of the installation cylinder, a reactor located in the upper part of the installation cylinder, a heating element located in the reactor, an atomizing nozzle located at the top of the reactor, a three-way valve located at the liquid inlet of the atomizing nozzle with one inlet connected to an external gas supply device and the other inlet connected to the liquid supply pump, a spray filter assembly with an air inlet connected to the reactor inside the installation cylinder for filtering exhaust gas, and a sealing and feeding assembly located in the middle of the installation cylinder and below the reactor; the sealing and feeding assembly includes: a sealing shell fixed inside the installation cylinder, and a component rotatably disposed inside the sealing shell to fill the inner cavity of the sealing shell. The system comprises a rotating sealing plate divided into multiple independent chambers along the circumference; a feed inlet located at the top of the sealing shell and connected to the reactor feed port; a discharge port located at the bottom of the sealing shell; a cooling chamber located inside the rotating sealing plate; a coolant inlet and a coolant outlet located on the top and bottom surfaces of the rotating sealing plate and connected to the cooling chamber; a rotary joint installed at the coolant inlet and coolant outlet and connected to external coolant equipment; a drive assembly located at the bottom of the sealing shell for driving the rotating sealing plate to rotate continuously; and a discharge pipe located at the bottom of the mounting cylinder. The feed inlet is directly opposite only one of the chambers.

2. The piezoelectric powder continuous production apparatus according to claim 1, characterized in that: The rotating sealing plate is a cross-shaped sealing plate that divides the inner cavity of the sealing shell into four chambers with an included angle of 90° between adjacent chambers, and the inlet and outlet are offset by 180° in the circumferential direction.

3. The piezoelectric powder continuous production apparatus according to claim 1, characterized in that: The rotating sealing plate is welded together from the left half shell and the right half shell, and a cooling chamber is formed inside it; at least one flow guide baffle is provided in the cooling chamber to guide the coolant to flow along a predetermined path, so that the coolant flows through each blade area.

4. The piezoelectric powder continuous production apparatus according to claim 1, characterized in that: The blade edge of the rotary sealing plate is provided with an elastic sealing strip; the sealing strip is made of polytetrafluoroethylene and carbon fiber.

5. The piezoelectric powder continuous production apparatus according to claim 1, characterized in that: The drive assembly includes a driven gear sleeved on the outer wall of the coolant outlet and a drive motor installed at the bottom of the sealed housing. The output end of the drive motor is provided with a driving gear that meshes with the driven gear.

6. The piezoelectric powder continuous production apparatus according to claim 1, characterized in that: The spray filtration assembly includes a spray housing, a drain pipe disposed on one side of the bottom of the spray housing, an air inlet pipe disposed on the side wall of the spray housing and above the drain pipe and connected to the reactor, multiple packing layers disposed at intervals inside the spray housing and above the air inlet pipe, and multiple spray pipes disposed inside the spray housing and respectively located directly above each packing layer.

7. The piezoelectric powder continuous production apparatus according to claim 1, characterized in that: The liquid supply pump is a peristaltic pump; the atomizing nozzle is a dual-fluid atomizing nozzle.

8. The piezoelectric powder continuous production apparatus according to claim 1, characterized in that: The reactor is equipped with multiple baffles arranged at an angle.

9. The piezoelectric powder continuous production apparatus according to claim 1, characterized in that: The heating element is a silicon carbide infrared radiation tube.

10. A method for continuous production of piezoelectric powder, characterized in that: Includes the following steps: S1. Prepare the precursor solution; S2. The liquid supply pump and the external gas supply equipment continuously deliver the precursor liquid and the gas at a certain flow rate to the atomizing nozzle, respectively, and atomize the precursor liquid into micron-sized droplets and continuously spray it into the reaction furnace. S3. The high temperature inside the reactor causes the droplets to thermally decompose and continuously generate solid powder; S4. At high temperatures, solid powder crystallizes into piezoelectric powder; S5. Piezoelectric powder continuously falls into the feed port and enters a chamber of the rotary sealing plate. The drive mechanism drives the rotary sealing plate to rotate continuously. The chamber containing the powder rotates to the discharge port and is discharged. At the same time, coolant continuously enters the cooling chamber through the rotary joint to cool the rotary sealing plate and the powder. S6. The discharged piezoelectric powder is continuously collected through the discharge pipe; S7. The exhaust gas enters the spray casing through the intake pipe for purification before being discharged.

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