Hydrothermal reaction kettle for strengthening dynamic mixing

Abstract

The utility model belongs to the technical field of chemical equipment, and discloses a hydrothermal reaction kettle for strengthening dynamic mixing, which comprises a kettle body, a heating device and a sealing cover, a polytetrafluoroethylene lining is arranged in the kettle body, and a propeller blade is fixed at the bottom of the polytetrafluoroethylene lining; a magnetic coupling driver is arranged on the outer side of the sealing cover and drives a magnetic stirrer arranged in the kettle body, and the magnetic stirrer is coaxially connected with the propeller blade; an ultrasonic transducer is embedded into the side wall of the kettle body and is electrically connected with an ultrasonic generator arranged outside the kettle body; the magnetic coupling driver and the ultrasonic generator are electrically connected with the control assembly. Through the ultrasonic transducer and the magnetic stirrer, mechanical stirring and ultrasonic cavitation are synergistic, the axial flow speed is increased, and a low-speed flow area is reduced, so that the problems that the magnetic field intensity is limited, sufficient mixing of a high-viscosity or solid-liquid mixed system is difficult to realize, and an eddy current dead zone is easy to generate during high-speed rotation are solved; and the axial flow velocity is increased, and the synthesis time is shortened, so that the distribution is more uniform.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, specifically relating to a hydrothermal reactor for enhanced dynamic mixing. Background Technology

[0002] Hydrothermal reaction equipment is widely used in fields such as nanomaterials and crystal synthesis. Its core function is to promote uniform mass and heat transfer of reactants through a high-temperature and high-pressure environment. For example, in the existing technology, Chinese utility model patent application number CN201520750114.8 discloses a hydrothermal synthesis reactor, specifically disclosing a hydrothermal synthesis reactor, including a support frame, on which an electric furnace group is fixedly installed, and the reactor body is located inside the electric furnace group; the characteristic feature is that the upper end of the reactor body is also provided with a reactor lid assembly to seal the reactor body, and a heat transfer tube passes through the reactor lid assembly and enters the reactor body along the edge of the reactor body; the heat transfer tube has a spiral disc structure at the bottom of the reactor body; a magnetic stirrer is also provided at the upper end of the reactor lid assembly, the stirring shaft of the magnetic stirrer extends into the reactor body, the lower end of the stirring shaft is provided with stirring blades, and a servo motor that drives the stirring shaft to rotate is located on the support frame; a reactor body tilting device is provided at the lower end of the reactor lid assembly and fixedly connected to the edge of the reactor body. The hydrothermal synthesis reactor using the above scheme has a scientific and reasonable structure, is easy to operate, is suitable for large-scale industrial production, and has good sealing performance.

[0003] However, in the above-mentioned devices, although magnetic coupling stirring can avoid leakage, it is difficult to achieve full mixing of high viscosity or solid-liquid mixtures due to the limitation of magnetic field strength, and eddy current dead zones are easily generated when rotating at high speed. Summary of the Invention

[0004] Based on this, this application provides a hydrothermal reactor for enhanced dynamic mixing to solve the problems that although magnetic coupling stirring can avoid leakage, it is difficult to achieve full mixing of high viscosity or solid-liquid mixtures due to the limitation of magnetic field strength, and eddy current dead zones are easily generated when rotating at high speed.

[0005] The technical solution to the above-mentioned technical problems in this application is as follows:

[0006] A hydrothermal reactor for enhanced dynamic mixing includes a reactor body, a heating device, and a sealing cover, and further includes:

[0007] The vessel body is lined with a polytetrafluoroethylene (PTFE) liner, and a titanium alloy propeller blade is fixed to the lower part of the PTFE liner. A magnetic coupling actuator is provided on the outside of the sealing cover, which magnetically drives a magnetic stirrer built into the vessel body. The magnetic stirrer is coaxially connected to the propeller blade. At least two ultrasonic transducers are embedded in the side wall of the vessel body. The ultrasonic transducers are spaced apart along the axial direction of the vessel body and are electrically connected to an ultrasonic generator located outside the vessel body. Both the magnetic coupling actuator and the ultrasonic generator are electrically connected to a control component, which is used to control the magnetic coupling actuator and the ultrasonic generator to work alternately or synchronously.

[0008] Preferably, the surface of the propeller blade has a plurality of guide holes radially distributed thereon.

[0009] Preferably, the propeller blade has a blade tilt angle of 15° to 45° and the blade edge has a serrated structure.

[0010] Preferably, a guide groove is provided on the wall of the guide hole.

[0011] Preferably, a waste heat recovery pipe is provided on the outside of the vessel body, and the outlet of the waste heat recovery pipe is connected to the air inlet of the heating device. The waste heat recovery pipe is used to recover heat energy during the cooling stage.

[0012] Preferably, the bottom of the magnetic stirrer is provided with a groove, and the center of the propeller blade is provided with a conical protrusion, the conical protrusion being detachably connected to the groove.

[0013] Preferably, the surface of the magnetic stir bar is coated with a silicon carbide wear-resistant layer.

[0014] Preferably, the inner wall of the polytetrafluoroethylene liner is coated with a silica superhydrophobic coating.

[0015] Preferably, the control component includes a first switch and a second switch. The first switch is electrically connected to the magnetic coupling driver and is used to turn the magnetic coupling driver on or off. The second switch is electrically connected to the ultrasonic generator and is used to turn the ultrasonic generator on or off.

[0016] The technical solution adopted in this application can achieve the following beneficial effects:

[0017] 1. By setting up an ultrasonic transducer and a magnetic stirrer, mechanical stirring and ultrasonic cavitation work together to increase the axial flow velocity and reduce the low-speed flow region. This solves the problem that it is difficult to achieve full mixing of high-viscosity or solid-liquid mixtures due to the limitation of magnetic field strength, and the problem that eddy dead zones are easily generated when rotating at high speed. At the same time, by increasing the axial flow velocity, the synthesis time of nanomaterials is shortened and the particle size distribution of the product is more uniform.

[0018] 2. By setting up an ultrasonic transducer, electrical energy is converted into high-frequency vibration, which generates microbubbles in the liquid phase and collapses instantly, forming local high temperature and high pressure, which accelerates the dissolution and mass transfer of reactants.

[0019] 3. The magnetic coupling driver transmits torque through non-contact magnetic force, driving the titanium alloy propeller blades to rotate, achieving uniform mixing at high speeds while ensuring overall sealing. Attached Figure Description

[0020] Figure 1 This is an overall schematic diagram of the hydrothermal reactor for enhanced dynamic mixing according to this application.

[0021] Figure 2 This is a partial front view of the hydrothermal reactor for enhanced dynamic mixing according to this application.

[0022] Figure 3 for Figure 2 AA cross-section view.

[0023] Figure 4 This is a partial exploded view of the hydrothermal reactor for enhanced dynamic mixing according to this application.

[0024] Figure 5 This is a partial schematic diagram of the hydrothermal reactor for enhanced dynamic mixing according to this application. Figure 1 .

[0025] Figure 6 This is a partial schematic diagram of the hydrothermal reactor for enhanced dynamic mixing according to this application. Figure 2 .

[0026] Figure 7 This is a partial schematic diagram of the hydrothermal reactor for enhanced dynamic mixing according to this application. Figure 3 .

[0027] In the figure: vessel body 100, ultrasonic transducer 110, ultrasonic generator 120, polytetrafluoroethylene liner 130, propeller blade 140, groove 141, flow guide hole 142, heating device 200, waste heat recovery pipe 210, sealing cover 300, magnetic coupling driver 310, magnetic stir bar 320, conical protrusion 321, control component 330, first switch 331, second switch 332. Detailed Implementation

[0028] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this application.

[0029] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," "top," "bottom," "end," "top," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] Please see Figures 1 to 7 This application provides a hydrothermal reactor for enhanced dynamic mixing, including a reactor body 100, a heating device 200, and a sealing cover 300. It further includes: a polytetrafluoroethylene (PTFE) liner 130 inside the reactor body 100, with a titanium alloy propeller blade 140 fixed to the bottom of the PTFE liner 130; a magnetic coupling actuator 310 on the outside of the sealing cover 300, which magnetically drives a magnetic stir bar 320 embedded in the reactor body 100, the magnetic stir bar 320 being coaxially connected to the propeller blade 140; at least two ultrasonic transducers 110 embedded in the sidewall of the reactor body 100, the ultrasonic transducers 110 being spaced apart along the axial direction of the reactor body 100 and electrically connected to an ultrasonic generator 120 disposed outside the reactor body 100; both the magnetic coupling actuator 310 and the ultrasonic generator 120 are electrically connected to a control component 330, the control component 330 being used to control the magnetic coupling actuator 310 and the ultrasonic generator 120 to work alternately or synchronously.

[0032] Specifically, the vessel body 100, the heating device 200, and the sealing cover 300 are all devices already disclosed in the prior art, and their specific structures will not be described in detail (for example, a magnetic stirring hydrothermal synthesizer disclosed in application number CN201721874443.9, and a hydrothermal reactor for preparing high-efficiency adsorption-type Ca-Al-LDHs powder materials disclosed in application number CN201920705920.1; the names of the features are different, but the specific structures and functions have been disclosed). The sealing cap 300 and the vessel body 100 are sealed by, but not limited to, threaded tightening or snap-fit ​​sealing. The polytetrafluoroethylene (PTFE) liner 130 is embedded in the inner wall of the vessel body 100, and the specific connection method can be a groove, hot compression, or other processes to form a corrosion-resistant reaction chamber. The titanium alloy propeller blade 140 is welded or bolted to the bottom of the PTFE liner 130, and the propeller blade 140 can rotate. It is made of a material that is compatible with strong acid / alkali environments. The magnetic coupling actuator 310 is installed on the outside of the sealing cap 300 and forms a non-contact magnetic coupling with the magnetic stir bar 320 inside the vessel body 100 through a permanent magnet or electromagnetic coil. The magnetic stir bar 320 and the propeller blade 140 are coaxially arranged. When the magnetic stir bar 320 rotates under the drive of the magnetic coupling actuator 310, the propeller blade rotates accordingly.

[0033] The ultrasonic transducers 110 are embedded in pre-drilled holes in the side wall of the vessel body 100, sealed with flanges, and axially spaced (e.g., top, middle, bottom, arranged vertically from top to bottom) to form a three-dimensional ultrasonic field. The ultrasonic transducers 110 are connected to the ultrasonic generator 120 via high-frequency cables or other electrical connections, and the ultrasonic generator 120 provides a specific frequency (e.g., 20kHz to 40kHz) of power input to drive the ultrasonic transducers 110 to generate a cavitation effect. Furthermore, the operating frequency of the ultrasonic transducers 110 is 20kHz to 100kHz, and the frequency difference between adjacent transducers is 10kHz to 20kHz. The control component 330 adopts, but is not limited to, push-button switches, and also includes a temperature sensor, a pressure sensor, a pH sensor, and a display screen. The temperature sensor, pressure sensor, and pH sensor are all housed within the polytetrafluoroethylene liner 130. The monitoring data is directly transmitted to the display screen. By viewing the monitoring data on the display screen, the operator can select whether the magnetic coupling driver 310 and the ultrasonic generator 120 work alternately or synchronously (synchronous operation means that stirring and ultrasonic waves work simultaneously to enhance mixing and mass transfer; alternating operation means that ultrasonic cleaning is started when stirring stops to prevent particle deposition).

[0034] Further, the reactants are loaded into a polytetrafluoroethylene (PTFE) liner 130 (volume not exceeding 80%) to ensure compatibility between corrosive substances and the PTFE liner 130 material. Sealing is achieved through a threaded sealing cap 300 linked to a magnetic coupling actuator 310. After manual pre-tightening, a vise is used for assisted locking. The magnetic coupling actuator 310 is activated via the control component 330, driving the propeller blades 140 for mechanical stirring (0 rpm to 1500 rpm). Simultaneously, the ultrasonic transducer 110 (20 kHz to 40 kHz) is activated, creating a cavitation effect. The heating device 200 heats the reactor to the target temperature (typically ≤230°C) at a preset rate. The pressure inside the reactor is maintained by the sealing structure and the pressure resistance (≤3 MPa) of the PTFE liner 130. A temperature sensor provides real-time data feedback to the display. The operator adjusts the heating power and stirring rate to improve reaction efficiency. After natural cooling to room temperature, the pressure is gradually released by rotating the sealing cap 300 counterclockwise using a vise to prevent sudden cooling and liner rupture.

[0035] The technical solution of the hydrothermal reactor for enhanced dynamic mixing adopted in this application can achieve the following beneficial effects:

[0036] 1. By setting up an ultrasonic transducer 110 and a magnetic stirrer 320, mechanical stirring and ultrasonic cavitation work together to increase the axial flow velocity and reduce the low-speed flow region. This solves the problem that it is difficult to achieve full mixing of high-viscosity or solid-liquid mixtures due to the limitation of magnetic field strength, and the problem that eddy dead zones are easily generated when rotating at high speed. At the same time, by increasing the axial flow velocity, the synthesis time of nanomaterials is shortened and the particle size distribution of the product is made more uniform.

[0037] 2. By setting up an ultrasonic transducer 110, electrical energy is converted into high-frequency vibration, which generates microbubbles in the liquid phase and collapses instantly, forming local high temperature and high pressure, which accelerates the dissolution and mass transfer of reactants.

[0038] 3. The magnetic coupling driver 310 transmits torque through non-contact magnetic force, driving the titanium alloy propeller blade 140 to rotate, achieving uniform mixing at high speeds while ensuring overall sealing.

[0039] Based on the above scheme, the surface of the propeller blade 140 is radially distributed with a number of guide holes 142.

[0040] The diameter of the guide holes 142 is 0.5 mm to 2 mm. The guide holes 142 are arranged radially along the blade of the propeller blade 140, and the spacing between two adjacent guide holes 142 is 2 to 5 times. When a conventional propeller blade rotates, the liquid forms a laminar boundary layer along the blade surface, which hinders the diffusion of reactants to the high concentration region. By setting the guide holes 142, the fluid is forced to pass through the guide holes 142 when the blade of the propeller blade 140 rotates, breaking the boundary layer stability and inducing the formation of local turbulence. Furthermore, the pressure difference between the front (high pressure region) and the back (low pressure region) of the blade forces the fluid to pass through the guide holes 142 at high speed, forming a microscale jet. After the jet collides with the main fluid, it generates a vortex ring structure, thereby enhancing micro-mixing.

[0041] Furthermore, to enhance turbulence intensity and address the issue of insufficient fluid shear force on the propeller blade 140, the blade inclination angle of the propeller blade 140 is 15° to 45°, and the blade edges are provided with a serrated structure (resembling owl wings or shark skin texture). For example, the blade of the propeller blade 140 is inclined from one end near the axis of the PTFE liner 130 to the other end, and the serration height is 0.1mm to 0.5mm. By adjusting the inclination, the relative angle of attack between the blade and the fluid is changed. When the inclination angle is between 15° and 45°, fluid separation at the leading edge of the blade (the end near the axis of the PTFE liner 130) is reduced, and the vortex intensity at the trailing edge (the edge of the serrated structure) is reduced, thereby improving propulsion efficiency. Setting the blade edge in a serrated shape generates counter-rotating micro-vortices (such as the "owl effect" in biomimetic design), delaying fluid separation and reducing turbulent drag. At the same time, the serrated structure reduces surface friction drag by interfering with boundary layer flow, similar to the drag reduction mechanism of shark skin texture. Furthermore, the above design effectively disperses the force on the blades, and the serrated structure reduces the vibration amplitude by weakening the eddy current impact, thereby extending the service life of the propeller blades 140.

[0042] In the above scheme, the guide hole 142 is provided with a guide groove on its wall, which can be a spiral groove or a wave groove. The inner wall of the guide hole 142 is designed with a spiral groove to form a spiral flow channel (similar to a thread structure), creating a rotating flow path. The spiral hole wall, through the geometric constraint of the flow channel, forces the fluid to move along the spiral path, generating a stable rotating flow field. At the same time, the centrifugal force generated by the swirling flow causes high-density particles in the fluid to aggregate towards the hole wall, and causes low-density media to migrate towards the center, achieving stratified flow. The spiral flow channel can reduce the turbulence intensity in the mainstream area and reduce energy loss. The spiral flow channel can also shorten the fluid mixing time. Similarly, the wave groove forms a wave-shaped flow channel (similar to a wave structure), creating an undulating flow path. The undulating wave structure periodically changes the flow channel cross-section, disrupting the formation of large-scale eddies. At the same time, the design of the wave crests and troughs can induce the fluid to accelerate at the troughs and decelerate at the crests, forming a local pressure gradient and promoting flow adhesion.

[0043] In a preferred embodiment of this application, a waste heat recovery pipe 210 is provided on the outside of the vessel body 100, and the outlet of the waste heat recovery pipe 210 is connected to the air inlet of the heating device 200. The waste heat recovery pipe 210 is used to recover heat energy during the cooling stage.

[0044] During the cooling stage of the vessel 100, the waste heat (typically 30°C to 150°C) carried by the high-temperature exhaust gas or cooling water is absorbed through the heat absorption section (the part in contact with the vessel 100) of the waste heat recovery pipe 210. The waste heat recovery pipe 210 uses a high-efficiency thermally conductive material (such as stainless steel or copper-aluminum composite pipe) and is filled with a phase change working fluid (such as water or ethanol). Heat transfer is achieved rapidly through the evaporation-condensation cycle of the working fluid. The recovered heat energy is conducted through the waste heat recovery pipe 210 to the exhaust port, where it exchanges heat with the cold air at the air inlet of the heating device 200. The cold air is preheated to 50°C to 80°C before entering the combustion chamber or heating system. Preheating the air reduces the heating requirement of the fuel while improving combustion efficiency and reducing heat energy waste.

[0045] In another preferred embodiment of this application, the magnetic stir bar 320 has a groove 141 at its bottom, and the propeller blade 140 has a conical protrusion 321 at its center. The conical protrusion 321 is detachably connected to the groove 141. The conical protrusion 321 and the groove 141 are matched and interlocked. When the groove 141 at the bottom of the magnetic stir bar 320 is inserted into the conical protrusion 321 at the center of the propeller blade 140, the conical surfaces contact (the conical angle is typically 30° to 60°) to generate a radial self-aligning effect, ensuring that the rotation axis coincides (eccentricity error < 0.05 mm) and avoiding vibration during high-speed rotation. The friction surfaces of the conical protrusion 321 and the groove 141 transmit torque through an interference fit (interference amount 0.01 mm to 0.03 mm), requiring no additional fasteners and making operation simple and convenient.

[0046] Based on the above solution, the surface of the magnetic stir bar 320 is coated with a silicon carbide wear-resistant layer. The coating thickness of the silicon carbide wear-resistant layer is 50μm to 200μm, and the Rockwell hardness is ≥80HRC. By applying the silicon carbide wear-resistant layer, the problem of shortened lifespan of the magnetic stir bar 320 due to wear is reduced, and the service life of the stir bar is extended.

[0047] In another embodiment of this application, the inner wall of the polytetrafluoroethylene liner 130 is coated with a silica superhydrophobic coating; the silica superhydrophobic coating has a thickness of 10 μm to 50 μm, and the silica superhydrophobic coating is doped with nano-alumina particles, with a doping ratio of 5% to 15% of the coating mass. For further refinement of the specific ratio, refer to the silica superhydrophobic coating commonly used in the chemical industry; and the silica superhydrophobic coating is easy to peel off at high temperatures, which improves the temperature resistance of the coating. Because of this property, it is often used in the chemical industry to improve the temperature resistance of equipment.

[0048] In another embodiment of this application, the control component 330 includes a first switch 331 and a second switch 332. The first switch 331 is electrically connected to the magnetic coupling driver 310 and is used to turn the magnetic coupling driver 310 on or off. The second switch 332 is electrically connected to the ultrasonic generator 120 and is used to turn the ultrasonic generator 120 on or off.

[0049] The first switch 331 and the second switch 332 are, but are not limited to, push-button or toggle types, etc., allowing the operator to turn the magnetic coupling driver 310 and the ultrasonic generator 120 on or off by pressing or flicking them. Preferably, the control component 330 also includes a first adjustment knob and a second adjustment knob. The first adjustment knob is electrically connected to the magnetic coupling driver 310, changing its rotation speed. Similarly, the second adjustment knob is electrically connected to the ultrasonic generator 120, adjusting its vibration frequency. The first and second adjustment knobs are similar to volume knobs on a radio, and their specific structures will not be described in detail. Using the first switch 331 and the second switch 332 to adjust the on / off state of the magnetic coupling driver 310 and the ultrasonic generator 120 makes control simpler and more convenient.

[0050] The above embodiments merely illustrate several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A hydrothermal reactor for enhanced dynamic mixing, comprising a reactor body, a heating device, and a sealing cover, characterized in that, include: The inside of the vessel body is lined with polytetrafluoroethylene (PTFE), and a propeller blade made of titanium alloy is fixed to the lower part of the PTFE lining. The outer side of the sealing cover is equipped with a magnetic coupling driver, which drives a magnetic stirrer built into the vessel body through magnetic force. The magnetic stirrer is coaxially connected to the propeller blade. At least two ultrasonic transducers are embedded in the side wall of the vessel body. The ultrasonic transducers are spaced apart along the axial direction of the vessel body and are electrically connected to an ultrasonic generator disposed outside the vessel body. Both the magnetic coupling driver and the ultrasonic generator are electrically connected to the control component, which is used to control the magnetic coupling driver and the ultrasonic generator to work alternately or synchronously.

2. The hydrothermal reactor for enhanced dynamic mixing as described in claim 1, characterized in that, The surface of the propeller blade has several guide holes distributed radially.

3. The hydrothermal reactor for enhanced dynamic mixing as described in claim 2, characterized in that, The propeller blades have an inclination angle of 15° to 45° and serrated edges.

4. The hydrothermal reactor for enhanced dynamic mixing as described in claim 2, characterized in that, The flow guide hole has a flow guide groove on its wall.

5. The hydrothermal reactor for enhanced dynamic mixing as described in claim 1, characterized in that, The vessel body is equipped with a waste heat recovery pipe on its exterior. The outlet of the waste heat recovery pipe is connected to the air inlet of the heating device. The waste heat recovery pipe is used to recover heat energy during the cooling stage.

6. The hydrothermal reactor for enhanced dynamic mixing as described in claim 1, characterized in that, The bottom of the magnetic stirrer is provided with a groove, and the center of the propeller blade is provided with a conical protrusion, which is detachably connected to the groove.

7. The hydrothermal reactor for enhanced dynamic mixing as described in claim 6, characterized in that, The surface of the magnetic stir bar is coated with a silicon carbide wear-resistant layer.

8. The hydrothermal reactor for enhanced dynamic mixing as described in claim 1, characterized in that, The inner wall of the polytetrafluoroethylene liner is coated with a silica superhydrophobic coating.

9. The hydrothermal reactor for enhanced dynamic mixing as described in claim 1, characterized in that, The control component includes a first switch and a second switch. The first switch is electrically connected to the magnetic coupling driver and is used to turn the magnetic coupling driver on or off. The second switch is electrically connected to the ultrasonic generator and is used to turn the ultrasonic generator on or off.

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