Glass stirring paddle applied to reaction kettle

Abstract

The invention discloses a glass stirring paddle applied to a reaction kettle, and belongs to the technical field of chemical equipment. The stirring paddle comprises a glass main shaft, a connecting end, a paddle structure, a reinforcing rib and an anti-corrosion film layer, the main shaft is made of high borosilicate glass, and the connecting end is a metal insert packaged at the top of the main shaft and is used for realizing stable connection with driving devices such as a synchronizing wheel and a motor shaft; the paddle structure is integrally connected to the lower portion of the main shaft in a hot melting forming mode, and glass reinforcing ribs are arranged on the surface of the paddle structure to improve the structural strength. The outer surfaces of the blades and the main shaft are coated with anti-corrosion film layers which are used for enhancing the chemical corrosion resistance of the blades and the main shaft. The preparation method comprises the steps of raw material melting, mold forming, thermal annealing, connecting end packaging, film layer attaching and the like, and good process controllability and airtight performance are achieved. The problems that an existing stirring paddle is poor in corrosion resistance, unstable in structure, incompatible in connector and the like in a high-corrosion and high-purity reaction environment are solved, and the stirring paddle has excellent mechanical strength, chemical inertness and adaptability, is suitable for high-requirement stirring operation in various reaction kettle systems and has good industrial application prospects.

Description

Technical Field

[0001] The invention relates to the technical field of chemical equipment, in particular to a glass stirring paddle used in a reaction kettle. Background Art

[0002] As the core mass transfer and heat transfer component in the reactor, the agitator is widely used in the process of liquid mixing, solid-liquid suspension, reaction enhancement, and other processes in the chemical, pharmaceutical, food, electronic materials and other industries. The agitator in traditional reactors is usually made of materials such as stainless steel, titanium alloy, and coated lining metal. It has good mechanical strength and processing performance and is suitable for most general industrial scenarios. However, with the increasing demand for the application of high-purity and highly corrosive process media, metal materials have shown obvious limitations in some occasions. For example, they are prone to corrosion in strong acid and strong alkali systems, which in turn causes problems such as ion precipitation, reaction contamination, and equipment corrosion damage, affecting the quality of the final product and the service life of the equipment.

[0003] To address the above-mentioned issues, some high-end process fields have gradually attempted to use non-metallic materials, such as fluoroplastics, ceramics, and glass materials, to prepare stirring paddles. Among them, borosilicate glass is considered to be an ideal material for reaction equipment components in corrosive environments due to its excellent thermal stability, chemical inertness, and good molding process. However, the application of glass stirring paddles in industrial practice still faces many challenges: on the one hand, glass itself is very brittle and has relatively low structural strength, and is prone to breakage or fracture during high-speed rotation or sudden load changes; on the other hand, glass material is difficult to achieve a firm and reliable connection with metal bearings and motor transmission mechanisms, and its airtight packaging and power transmission capabilities are weak, which limits its stable operation in high-demand stirring environments.

[0004] Furthermore, some existing glass stirring paddles lack effective structural reinforcement design and packaging process control during the manufacturing process, often using simple welding, gluing, or bayonet connections. This makes it difficult to achieve long-term corrosion resistance, reliable sealing, and compatibility with a variety of reactor drive structures. To address this situation, there is an urgent need to provide a glass stirring paddle with high structural strength, good airtightness, strong chemical inertness, and excellent adaptability, as well as a preparation method. This paddle can meet the stringent requirements of special process media for material purity and corrosion resistance, while also ensuring safety and industrial mass production capabilities.

[0005] Therefore, it is urgent to construct a glass stirring paddle for use in a reactor to solve the above problems. Summary of the Invention

[0006] The object of the present invention is to provide a glass stirring paddle for use in a reactor to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: a glass stirring paddle for a reactor, comprising:

[0008] The agitator shaft, connecting end, blade structure, reinforcement ribs and anti-corrosion film layer;

[0009] Wherein, the main shaft of the stirring paddle is a hollow tube made of high borosilicate glass;

[0010] The connecting end is a metal insert encapsulated inside the upper end of the main shaft, and its exterior is provided with a synchronous wheel for mounting, thereby realizing the mechanical connection and torque transmission between the stirring paddle and the external drive mechanism;

[0011] The blade structure is connected to the main shaft by hot melt molding, and is arranged in a three-blade or four-blade spiral with an inclination angle of 20°-45°, a blade thickness of 3-6mm, and a blade length of 50-200mm;

[0012] The reinforcing ribs are arranged along the blade structure, have a thickness of 1-3 mm, and are integrally formed with the blade;

[0013] The anti-corrosion film layer is applied to the blade structure and the outer surface of the main shaft at a laminating temperature of 180-200° C., a pressure of 0.3-0.5 MPa, and a peeling strength of not less than 2 N / mm.

[0014] As a preferred technical solution of the present invention: the anti-corrosion film layer is a polytetrafluoroethylene film with a thickness of 0.2 mm, which is resistant to acid and alkali corrosion and is suitable for chemical media with a pH value of 1-13.

[0015] As a preferred technical solution of the present invention: the connecting end is made of stainless steel or titanium alloy, the surface is roughened by sandblasting and coated with silane coupling agent, and is packaged in the main shaft by high temperature melting at 800-1000℃ to form an airtight bonding structure. The leakage rate after packaging is less than 10 -6 Pa·m 3 / s.

[0016] As a preferred technical solution of the present invention: the raw material formula of the high borosilicate glass includes: 70-75 parts by weight of SiO2, 10-15 parts by weight of B2O3, 5-10 parts by weight of Al2O3, 3-5 parts by weight of ZrO2, and 5-8 parts by weight of Na2O.

[0017] As a preferred technical solution of the present invention: the reinforcing rib is integrally formed from high borosilicate glass and is integral with the blade structure, and its impact strength is not less than 150 MPa.

[0018] As a preferred technical solution of the present invention: the glass stirring paddle is suitable for a temperature range of -50°C to 250°C, an operating speed of 10 to 300 rpm, and is suitable for a high-temperature and high-corrosion reactor environment.

[0019] The present invention also proposes a method for preparing a glass stirring paddle for use in a reactor, comprising the following steps:

[0020] (a) Raw Material Preparation and Melting: 70-75 parts by weight of SiO2, 10-15 parts by weight of B2O3, 5-10 parts by weight of Al2O3, 3-5 parts by weight of ZrO2, and 5-8 parts by weight of Na2O were weighed according to the formula, mixed, placed in a high-purity alumina crucible, and melted in an electric furnace at 1400-1500°C for 3-5 hours with stirring at 50-100 rpm to remove bubbles, to form a uniform glass melt;

[0021] (b) Molding and Heat Treatment: The glass melt is poured into a precision mold preheated to 500-600°C. A three-blade or four-blade propeller with an inclination angle of 20°-45° and a thickness of 3-6 mm is formed by blowing at 0.1-0.3 MPa or die-casting at 0.5-1 MPa. The propeller is kept at this temperature for 30-60 minutes and then slowly cooled to 300°C. After demolding, the propeller is annealed at 600-800°C for 1-3 hours at a heating rate of 5-10°C / min and a cooling rate of 1-5°C / min to room temperature.

[0022] (c) Lamination of the connection end with the anti-corrosion film: The metal insert is sandblasted to a roughness of Ra1.6-3.2μm, the surface is coated with silane coupling agent, dried and preheated to 200-300℃, and then packaged with the annealing spindle at 800-1000℃ for 10-20 minutes;

[0023] After plasma treatment, the anti-corrosion film is applied to the surface of the blade and the main shaft at a temperature of 180-200°C, a pressure of 0.3-0.5 MPa, for 5-10 minutes, and then cooled to room temperature.

[0024] (d) Quality test: Corrosion resistance is tested by immersing in 10 mol / L HCl or NaOH for 72 hours;

[0025] The drop hammer test applies an impact force of 100-200 MPa to test the impact resistance;

[0026] Run at 5000rpm for 100 hours to verify the air tightness of the connection end, and the leakage rate is less than 10 -6 Pa·m 3 / s.

[0027] As a preferred technical solution of the present invention: the stirring speed during the melting process is 50-100 rpm, ensuring that the glass melt is uniform, transparent and free of bubbles.

[0028] As a preferred technical solution of the present invention: the precision mold is made of high-temperature resistant stainless steel or ceramic material, the surface is sprayed with boron nitride or aluminum oxide release agent, the mold preheating temperature is controlled at 500-600°C, and the mold is cleaned with deionized water after demoulding.

[0029] As a preferred technical solution of the present invention: the quality inspection further includes:

[0030] Use an ultrasonic flaw detector to detect whether there are micro cracks in the blade structure and main shaft, with a resolution of not less than 0.1mm;

[0031] Use a microscope to observe the surface integrity of the anti-corrosion film to ensure there are no bubbles or peeling;

[0032] Immerse in 10mol / LHCl or NaOH solution at 200℃ for 48 hours to test the overall durability.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] By selecting highly inert and stable borosilicate glass as the main body of the stirring paddle, the corrosion, rust, or metal ion precipitation that can occur with traditional metal stirring paddles in acidic, alkaline, or oxidizing reaction media is effectively avoided, reducing the risk of contamination at the source and improving the chemical purity of the reaction system. At the same time, the surface of the stirring paddle is coated with a special polymer anti-corrosion film, further enhancing its corrosion resistance. It is particularly suitable for fields such as pharmaceuticals, fine chemicals, and high-end materials, which have strict requirements on product purity. Furthermore, the glass material has excellent thermal stability and can adapt to large temperature fluctuations and continuous operation, significantly enhancing the product's applicability and reliability in complex working conditions.

[0035] This agitator adopts a multi-piece spiral blade structure with optimized inclination angle and spatial distribution, which effectively enhances fluid disturbance and mixing efficiency. The blades and the main shaft are integrally formed through a hot-melt process to form an integrated structure without mechanical gaps, avoiding the risk of loosening, eccentricity or breakage during operation. At the same time, molded glass reinforcement ribs are arranged on the surface of the blades to significantly improve their impact resistance, torsion resistance and bending resistance, meeting the requirements of complex operating conditions such as long-term continuous stirring and periodic load impact. An embedded metal connection end is provided at the top of the main shaft, which is fixed to the inside of the glass through a specially designed sealing and melting process. The connection part has a stable structure and strong sealing, which not only ensures that the medium does not leak during the stirring process, but also maintains the stability of power transmission under high-speed rotation, effectively extending the service life of the equipment.

[0036] The structural design of the present invention fully considers the interface compatibility with existing reactor drive systems. The metal connection end can be flexibly adapted to various drive components such as synchronous wheels, couplings, or standard motor shafts, allowing users to directly integrate and use without the need for additional modification. At the same time, its manufacturing process is highly standardized. Key steps such as melt batching, thermoforming, annealing, and film lamination can all be implemented in batches on existing industrial production lines, making it reproducible and scalable. Due to its multiple advantages in corrosion resistance, structural reliability, and adaptability, it is particularly suitable for chemical reaction equipment with high cleanliness and high safety requirements, and has significant engineering application potential and market promotion prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces and describes the drawings required for use in the embodiments of the present invention or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0038] Figure 1 : A structural schematic diagram of a glass stirring paddle applied to a reactor of the present invention.

[0039] Among them, 1 is the main shaft of the stirring paddle; 2 is the connecting end; 3 is the blade structure; 4 is the reinforcing rib. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, rather than all the embodiments.

[0041] Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative effort shall fall within the scope of protection of the present invention. In order to more clearly explain and illustrate the technical solutions and implementations of the present invention, the following describes preferred specific examples for implementing the technical solutions of the present invention.

[0042] See Figure 1The present invention provides a glass stirring paddle, comprising a stirring paddle main shaft 1, a connecting end 2, a blade structure 3, a reinforcing rib 4 and an anti-corrosion film layer. The main shaft is made of high borosilicate glass into a hollow round tube with a diameter of 20 mm and a wall thickness of 2 mm. The raw material formula is 72 parts by weight of SiO2, 12 parts by weight of B2O3, 8 parts by weight of Al2O3, 4 parts by weight of ZrO2, and 6 parts by weight of Na2O. The temperature range is -50°C to 250°C, and the pH resistance is 1-13. The connecting end is made of 316L stainless steel, the surface is sandblasted to Ra 2.0μm, coated with silane coupling agent KH-550, and packaged at 900°C for 15 minutes. The leakage rate is less than 10 -6 Pa·m 3 / s, with external synchronous gear grooves for torque transmission. The propeller blades are connected to the main shaft via hot-melt molding and are arranged in a three-lobed spiral with a 30° inclination angle, a blade thickness of 4mm, and a length of 100mm. The reinforcing ribs are 2mm thick and integrally molded with the propeller blades, with an impact strength of 160MPa. The anti-corrosion coating is a 0.2mm thick polytetrafluoroethylene (PTFE) film, bonded to the propeller blade and main shaft surfaces at 190°C, 0.4MPa, and 8 minutes. The peel strength is 2.5N / mm, and it is pH 1-13 resistant.

[0043] The preparation method includes the following steps: weighing the raw materials according to the formula, placing them in a high-purity alumina crucible, melting them at 1450°C for 4 hours, stirring at 80 rpm, and ensuring that the melt is uniform and free of bubbles. The melt is injected into a high-temperature resistant stainless steel mold preheated to 550°C, spraying a boron nitride release agent on the surface, and using a 0.2MPa blow-molded three-blade paddle. The mold is kept warm for 45 minutes, slowly cooled to 300°C, and annealed at 700°C for 2 hours after demolding, with a heating rate of 8°C / min and a cooling rate of 3°C / min. The mold is cleaned with deionized water. The connecting end is sandblasted to Ra 2.0μm, coated with KH-550, preheated to 250°C, and then packaged with the main shaft at 900°C for 15 minutes. The PTFE membrane is bonded after plasma treatment under the conditions of 190°C, 0.4MPa, and 8 minutes, and then cooled to room temperature. Quality testing includes: 10mol / L HCl and NaOH immersion for 72 hours to verify corrosion resistance; 150MPa drop hammer test to confirm impact resistance; 5000rpm operation for 100 hours to verify leakage rate is less than 10 -6 Pa·m 3 / s; ultrasonic flaw detector (resolution 0.1mm) to detect micro cracks; microscopic inspection to check if there are bubbles or peeling of PTFE membrane; immersion in 10mol / L HCl or NaOH at 200℃ for 48 hours to verify durability.

[0044] The stirring paddle is suitable for reactor environments with temperatures ranging from -50°C to 250°C and 10-300 rpm. It has been tested for 500 hours in pH 2 sulfuric acid and pH 12 sodium hydroxide solutions with no surface corrosion, stable mechanical properties, and a three-leaf helical design that optimizes mixing efficiency. The titanium alloy connection end is roughened to Ra 2.5μm, coated with KH-560, and sealed at 950°C for 12 minutes with a gas leakage rate of less than 10%. -6 Pa·m 3 The four-blade paddle (inclination angle 40°, thickness 5mm, length 150mm) was bonded at 0.5MPa and 200℃, and the peel strength was 2.8N / mm. The test results were consistent, indicating that the process has strong adaptability.

[0045] The contents not described in detail in this specification belong to the prior art known to professional and technical personnel in this field. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A glass stirring paddle used in a reactor, characterized in that: include: A stirring paddle main shaft (1), a connecting end (2), a blade structure (3), a reinforcing rib (4) and an anti-corrosion film layer; Wherein, the stirring paddle main shaft (1) is a hollow circular tube made of high borosilicate glass; The connecting end (2) is a metal insert encapsulated inside the upper end of the main shaft, and is provided with a synchronous wheel on the outside thereof to achieve mechanical connection and torque transmission between the stirring blade and the external driving mechanism; The blade structure (3) is connected to the main shaft (1) by hot melt molding, and is arranged in a three-leaf or four-leaf spiral with an inclination angle of 20°-45°, a blade thickness of 3-6 mm, and a blade length of 50-200 mm; The reinforcing rib (4) is arranged along the blade structure, has a thickness of 1-3 mm, and is integrally formed with the blade; The anti-corrosion film layer is applied to the outer surface of the blade structure (3) and the main shaft (1) at a laminating temperature of 180-200° C., a pressure of 0.3-0.5 MPa, and a peeling strength of not less than 2 N / mm.

2. The glass stirring paddle for use in a reactor according to claim 1, characterized in that: The anti-corrosion film layer is a polytetrafluoroethylene film with a thickness of 0.2 mm, which is resistant to acid and alkali corrosion and is suitable for chemical media with a pH value of 1-13.

3. The glass stirring paddle for use in a reactor according to claim 1, characterized in that: The connecting end (2) is made of stainless steel or titanium alloy, the surface of which is roughened by sandblasting and coated with silane coupling agent, and is packaged in the main shaft (1) by high-temperature melting at 800-1000°C to form an airtight bonding structure. The air leakage rate after packaging is less than 10 -6 Pa·m 3 / s.

4. The glass stirring paddle for use in a reactor according to claim 1, characterized in that: The raw material formula of the high borosilicate glass includes: 70-75 parts by weight of SiO2, 10-15 parts by weight of B2O3, 5-10 parts by weight of Al2O3, 3-5 parts by weight of ZrO2, and 5-8 parts by weight of Na2O.

5. The glass stirring paddle according to claim 1, characterized in that: The reinforcing rib (4) is formed integrally with high borosilicate glass and is integral with the blade structure (3), and its impact strength is not less than 150 MPa.

6. The glass stirring paddle for use in a reactor according to claim 1, characterized in that: The glass stirring paddle is suitable for a temperature range of -50°C to 250°C, an operating speed of 10 to 300 rpm, and is suitable for a high-temperature and high-corrosion reactor environment.

7. A method for preparing a glass stirring paddle for use in a reactor according to any one of claims 1 to 6, characterized in that: The following steps are involved: (a) Raw Material Preparation and Melting: 70-75 parts by weight of SiO2, 10-15 parts by weight of B2O3, 5-10 parts by weight of Al2O3, 3-5 parts by weight of ZrO2, and 5-8 parts by weight of Na2O were weighed according to the formula, mixed, placed in a high-purity alumina crucible, and melted in an electric furnace at 1400-1500°C for 3-5 hours with stirring at 50-100 rpm to remove bubbles, to form a uniform glass melt; (b) Molding and Heat Treatment: The glass melt is poured into a precision mold preheated to 500-600°C. A three-blade or four-blade propeller with an inclination angle of 20°-45° and a thickness of 3-6 mm is formed by blowing at 0.1-0.3 MPa or die-casting at 0.5-1 MPa. The propeller is kept at this temperature for 30-60 minutes and then slowly cooled to 300°C. After demolding, the propeller is annealed at 600-800°C for 1-3 hours at a heating rate of 5-10°C / min and a cooling rate of 1-5°C / min to room temperature. (c) Lamination of the connection end with the anti-corrosion film: The metal insert is sandblasted to a roughness of Ra1.6-3.2μm, the surface is coated with silane coupling agent, dried and preheated to 200-300℃, and then packaged with the annealing spindle at 800-1000℃ for 10-20 minutes; After plasma treatment, the anti-corrosion film is applied to the surface of the blade and the main shaft at a temperature of 180-200°C, a pressure of 0.3-0.5 MPa, for 5-10 minutes, and then cooled to room temperature. (d) Quality test: Corrosion resistance is tested by immersing in 10 mol / L HCl or NaOH for 72 hours; The drop hammer test applies an impact force of 100-200 MPa to test the impact resistance; Run at 5000rpm for 100 hours to verify the air tightness of the connection end, and the leakage rate is less than 10 -6 Pa·m 3 / s.

8. The method according to claim 7, wherein: The stirring speed during the melting process is 50-100 rpm to ensure that the glass melt is uniform, transparent and free of bubbles.

9. The method according to claim 7, wherein: The precision mold is made of high-temperature resistant stainless steel or ceramic material, and the surface is sprayed with boron nitride or aluminum oxide release agent. The mold preheating temperature is controlled at 500-600°C, and the mold is cleaned with deionized water after demoulding.

10. The method according to claim 7, wherein: The quality inspection also includes: Use an ultrasonic flaw detector to detect whether there are micro cracks on the blade structure (3) and the main shaft (1), with a resolution of not less than 0.1 mm; Use a microscope to observe the surface integrity of the anti-corrosion film to ensure there are no bubbles or peeling; Immerse in 10mol / LHCl or NaOH solution at 200℃ for 48 hours to test the overall durability.

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