A high-efficiency and uniform microwave continuous-flow reaction device

Abstract

This invention proposes a highly efficient and uniform microwave continuous flow reactor, comprising a microwave single-mode resonant cavity, a microwave generator, and a continuous flow reactor. The microwave single-mode resonant cavity includes a circular waveguide, two rectangular-to-circular transducers, and two rectangular waveguides. The continuous flow reactor is a microchannel reactor, located within the cavity of the circular waveguide, used to carry continuous fluid material. The microwave generator includes two uniform microwave solid-state source radiators and two straight waveguides. The microwaves generated by the microwave solid-state source radiators enter the rectangular waveguides through the straight waveguides and isolators, and then the rectangular waveguide mode is converted to the circular waveguide mode by the rectangular-to-circular transducers. This makes the electromagnetic field polarization directions of the microwaves symmetrically transmitted from both sides of the circular waveguides orthogonal, generating electromagnetic waves with mutually orthogonal electric field directions in the circular waveguides. This allows the continuous fluid material inside the continuous flow reactor to be heated simultaneously by two orthogonal electromagnetic waves.

Description

Technical Field

[0001] This invention belongs to the field of microwave external field enhancement technology, specifically relating to a highly efficient and uniform microwave continuous flow reaction device. Background Technology

[0002] Driven by the requirements of clean and efficient production, environmental protection, and sustainable development, microwave technology, as a novel and green field enhancement technology, has made rapid progress in recent years in fields such as organic synthesis, drug development, analytical science, and petrochemicals.

[0003] Currently, batch microwave reactors are commonly used in laboratory organic synthesis reactions. However, the limited penetration depth of microwaves leads to uneven heating, directly affecting the production capacity of reaction products. Furthermore, the "hot spots" and "thermal runaway" phenomena generated during the operation of batch microwave reactors can pose significant threats to the safety of the organic synthesis process. Therefore, researchers have designed a microwave continuous flow tubular reactor by combining microwave heating with continuous flow chemistry. This reactor allows materials to flow continuously and uniformly from the tube under microwave heating. Compared to conventional heating, microwave heating is volumetric heating, resulting in faster heating speeds, less heat loss, and easier control; compared to batch reactors, continuous flow allows for more complete organic reactions.

[0004] Existing microwave continuous flow reactors include single-mode microwave continuous flow reactors, large-scale microwave continuous flow reactors, rectangular waveguide reactors, ridge waveguide reactors, circular waveguide microwave reactors, and planar waveguide reactors. However, they all suffer from drawbacks to some extent, such as uneven field distribution, insufficient utilization of microwave energy, slow processing speed, and large size, which limit the further application of microwave energy in organic synthesis reactions. Therefore, there is an urgent need to design a highly efficient and uniform microwave continuous flow reactor. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] This invention proposes a microwave continuous flow reactor that enables efficient, uniform, and safe heating of materials during organic synthesis reactions, solving the technical problems of low mass and heat transfer efficiency, inability to provide uniform radiation, and poor safety of traditional intermittent microwave reactors.

[0007] (II) Technical Solution

[0008] To address the aforementioned technical problems, this invention proposes a highly efficient and uniform microwave continuous flow reactor, which includes a microwave single-mode resonant cavity, a microwave generator, and a continuous flow reactor; wherein,

[0009] The microwave single-mode resonant cavity includes a circular waveguide, two rectangular-to-circular transducers, and two rectangular waveguides. The two ends of the circular waveguide are connected to the inner ends of one rectangular-to-circular transducer, and the outer ends of each rectangular-to-circular transducer are connected to the inner ends of one rectangular waveguide. The circular waveguide serves as the main body of the heating device, and its side walls are equipped with liquid inlet and liquid outlet pipes.

[0010] The continuous flow reactor is a microchannel reactor, which is set in the inner cavity of a circular waveguide to carry continuous fluid materials. The two ends of the microchannel reactor are connected to the inlet pipe and the outlet pipe, respectively.

[0011] The microwave generator includes two uniform microwave solid-state source radiators and two straight waveguides. The inner ends of the two straight waveguides are connected to the outer end of a rectangular waveguide through an isolator. The two uniform microwave solid-state source radiators are installed on the lower side of each straight waveguide. The microwaves generated by the microwave solid-state source radiators enter the rectangular waveguide through the straight waveguides and isolators. Then, the rectangular waveguide mode is converted to the circular waveguide mode by a rectangular-to-circular transducer, so that the electromagnetic field polarization directions generated by the microwaves symmetrically transmitted from both sides of the circular waveguide are orthogonal. This generates electromagnetic waves with mutually orthogonal electric field directions in the circular waveguide, so that the continuous fluid material inside the continuous flow reactor can be heated by the two orthogonal electromagnetic waves simultaneously.

[0012] Furthermore, the circular waveguide is a TE11 circular waveguide, and the rectangular waveguide is a TE10 rectangular waveguide.

[0013] Furthermore, the TE11 circular waveguide has a diameter of 90mm and a length of 400mm.

[0014] Furthermore, the inlet and outlet pipelines are connected by a peristaltic pump to achieve continuous feeding and discharging.

[0015] Furthermore, video monitoring probes are installed on the sidewalls of the circular waveguide to observe the changes in the state of the internal materials in real time.

[0016] Furthermore, multiple thermometers are installed at different locations on the sidewall of the circular waveguide.

[0017] Furthermore, the continuous flow reactor is a spiral quartz coil structure consisting of a single quartz tube spirally wound and placed inside a circular waveguide cavity, with the two ends of the spiral quartz coil connected to the inlet pipe and the outlet pipe, respectively.

[0018] Furthermore, a spiral quartz coil runs through the entire circular waveguide.

[0019] Furthermore, the outer diameter of the spiral quartz coil structure is 20mm, the inner diameter is 16mm, and the number of spiral coils of the quartz tube is 10.

[0020] Furthermore, the microwave frequency of the microwave solid-state source radiator 1 is 2450±25MHz.

[0021] (III) Beneficial Effects

[0022] This invention proposes a highly efficient and uniform microwave continuous flow reactor, comprising a microwave single-mode resonant cavity, a microwave generator, and a continuous flow reactor. The microwave single-mode resonant cavity includes a circular waveguide, two rectangular-to-circular transducers, and two rectangular waveguides. The continuous flow reactor is a microchannel reactor, located within the cavity of the circular waveguide, used to carry continuous fluid material. The microwave generator includes two uniform microwave solid-state source radiators and two straight waveguides. The microwaves generated by the microwave solid-state source radiators enter the rectangular waveguides through the straight waveguides and isolators, and then the rectangular waveguide mode is converted to the circular waveguide mode by the rectangular-to-circular transducers. This makes the electromagnetic field polarization directions of the microwaves symmetrically transmitted from both sides of the circular waveguides orthogonal, generating electromagnetic waves with mutually orthogonal electric field directions in the circular waveguides. This allows the continuous fluid material inside the continuous flow reactor to be heated simultaneously by two orthogonal electromagnetic waves.

[0023] The main beneficial effects of this invention include:

[0024] 1. Design of the Rectangular-to-Circular Waveguide Converter: By rationally designing the rectangular-to-circular waveguide converter, the electromagnetic field polarization directions of the two rectangular waveguides are made orthogonal, thereby generating TE11 mode electromagnetic waves with mutually orthogonal electric field directions in the circular waveguide. This design ensures uniform distribution of electromagnetic waves and effective heating in the heating device.

[0025] 2. Continuous flow heating with quartz coils: By placing quartz coils within a circular waveguide, a continuous fluid can be simultaneously heated by two orthogonal electromagnetic waves. This design ensures heating uniformity and improves heating efficiency.

[0026] 3. Installation of online monitoring system: By installing video monitoring probes and infrared thermometers, the reaction process can be detected and monitored in real time, thereby achieving intelligent and controllable process.

[0027] This invention provides a highly efficient and uniform microwave continuous flow reactor that can meet the needs of microwave continuous flow heating processes. It can achieve efficient, uniform, and safe heating of materials during organic synthesis reactions, solving the technical problems of low mass and heat transfer efficiency, inability to radiate uniformly, and poor safety of traditional intermittent microwave reactors. It has excellent economic, energy-saving, and environmental protection features. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the controllable continuous microwave high-efficiency heating device of the present invention;

[0029] Figure 2 This is a schematic diagram of the internal structure of the microwave single-mode resonant cavity in this invention.

[0030] In the diagram: 1-Microwave solid-state source radiator; 2-Straight waveguide; 3-Isolator; 4-TE10 rectangular waveguide; 5-Rectangular-to-circular converter; 6-TE11 circular waveguide; 7-Liquid outlet line; 8-First infrared thermometer; 9-Second infrared thermometer; 10-Third infrared thermometer; 11-Microwave single-mode resonant cavity; 12-Video monitoring probe; 13-Liquid inlet line; 14-Spiral quartz coil. Detailed Implementation

[0031] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0032] This embodiment proposes a highly efficient and uniform microwave continuous flow reaction device, such as... Figure 1 As shown, the microwave continuous flow reactor includes a microwave single-mode resonant cavity 11, a microwave generator, and a continuous flow reactor 14.

[0033] The microwave single-mode resonant cavity 11 includes a TE11 circular waveguide 6, two circular-to-rectangular transducers 5, and two TE10 rectangular waveguides 4. Each end of the TE11 circular waveguide 6 is connected to the inner end of a circular-to-rectangular transducer 5, and the outer end of each circular-to-rectangular transducer 5 is connected to the inner end of a TE10 rectangular waveguide 4. The TE11 circular waveguide 6 serves as the main body of the heating device, with an inlet pipe 13 and an outlet pipe 7 mounted on its side wall. The inlet pipe 13 and outlet pipe 7 are connected to the peristaltic pump for continuous feeding and discharging. In this embodiment, the TE11 circular waveguide 5 has a diameter of 90 mm and a length of 400 mm.

[0034] A video monitoring probe 12 is installed on the side wall of the TE11 circular waveguide 6 to observe the changes in the state of the internal materials in real time and understand the working status of the reaction system. In addition, a first infrared thermometer 8, a second infrared thermometer 9, and a third infrared thermometer 10 are installed at different positions on the side wall of the TE11 circular waveguide 6 to monitor the temperature changes of the entire system, thereby achieving controllable process temperature.

[0035] The continuous flow reactor 14 is a microchannel reactor used to carry continuous fluid materials. Specifically, it is a spiral quartz coil structure consisting of a single quartz tube spirally wound and placed inside the cavity of the TE11 circular waveguide 6. The two ends of the spiral quartz coil are connected to the inlet pipe 13 and the outlet pipe 7, respectively. The TE11 circular waveguide 6 and the continuous flow reactor 14 form a material heating zone.

[0036] In this embodiment, the outer diameter of the spiral quartz coil structure is 20mm, the inner diameter is 16mm, the number of spiral coils of the quartz tube is 10, the spiral quartz coil runs through the entire TE11 circular waveguide 6, the liquid holding capacity of the continuous fluid material is 450mL, it can withstand high pressure (10MPa) and high temperature (1200℃), and has high corrosion resistance, pressure resistance and temperature resistance.

[0037] The microwave generator includes two uniform microwave solid-state source radiators 1 and two straight waveguides 2. The inner ends of the two straight waveguides 2 are each connected to the outer end of a TE10 rectangular waveguide 4 via an isolator 3. The two uniform microwave solid-state source radiators 1 are respectively installed on the lower side of each straight waveguide 2. In this embodiment, the microwave frequency of the microwave solid-state source radiators 1 is 2450±25MHz. The generated microwaves enter the TE10 rectangular waveguide 4 through the straight waveguides 2 and isolators 3. Then, the mode of the TE10 rectangular waveguide 4 is converted to the mode of the TE11 circular waveguide 6 by a rectangular-to-circular waveguide converter 5. This results in the electromagnetic field polarization directions of the microwaves symmetrically transmitted from both sides of the TE11 circular waveguide 6 being orthogonal. This generates TE11 mode electromagnetic waves with mutually orthogonal electric field directions in the TE11 circular waveguide 6, allowing the continuous fluid material inside the continuous flow reactor 14 to be heated simultaneously by two orthogonal electromagnetic waves over a relatively wide dielectric range, thereby achieving highly efficient, rapid, and uniform heating of the material.

[0038] The efficient and uniform microwave continuous flow reactor of this invention is applicable to many fields and application scenarios, including but not limited to: 1) Chemical industry: for temperature-controlled heating of chemical reactions, such as catalytic reactions, synthesis reactions, and dissolution reactions; 2) Biopharmaceutical industry: for heating and temperature control of bioreactors, such as cell culture, fermentation, and enzyme reactions; 3) Food processing: for heating, sterilizing, and disinfecting food, such as heating liquid food, sterilizing fruit juice, and heating dairy products; 4) Material processing: for heat treatment and melting of materials; 5) Laboratory research: for heating experiments and temperature control in scientific research, such as physical experiments and materials research.

[0039] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A highly efficient and uniform microwave continuous flow reactor, characterized in that, The microwave continuous flow reactor includes a microwave single-mode resonant cavity, a microwave generator, and a continuous flow reactor; wherein... The microwave single-mode resonant cavity includes a circular waveguide, two rectangular-to-circular transducers, and two rectangular waveguides; wherein, the two ends of the circular waveguide are respectively connected to the inner end of a rectangular-to-circular transducer, and the outer end of each rectangular-to-circular transducer is connected to the inner end of a rectangular waveguide; the circular waveguide serves as the main body of the heating device, and liquid inlet and liquid outlet pipes are provided on its side wall; The continuous flow reactor is a microchannel reactor, which is set in the inner cavity of a circular waveguide to carry continuous fluid materials. The two ends of the microchannel reactor are connected to the inlet pipe and the outlet pipe, respectively. The microwave generator includes two uniform microwave solid-state source radiators and two straight waveguides. The inner ends of the two straight waveguides are connected to the outer end of a rectangular waveguide through an isolator. The two uniform microwave solid-state source radiators are installed on the lower side of each straight waveguide. The microwaves generated by the microwave solid-state source radiators enter the rectangular waveguide through the straight waveguides and isolators. Then, the rectangular waveguide mode is converted to the circular waveguide mode by a rectangular-to-circular transducer, so that the electromagnetic field polarization directions generated by the microwaves symmetrically transmitted from both sides of the circular waveguide are orthogonal. This generates electromagnetic waves with mutually orthogonal electric field directions in the circular waveguide, so that the continuous fluid material inside the continuous flow reactor can be heated by two orthogonal electromagnetic waves simultaneously.

2. The microwave continuous flow reactor as described in claim 1, characterized in that, The circular waveguide is a TE11 circular waveguide, and the rectangular waveguide is a TE10 rectangular waveguide.

3. The microwave continuous flow reactor as described in claim 2, characterized in that, The TE11 circular waveguide has a diameter of 90mm and a length of 400mm.

4. The microwave continuous flow reactor as described in claim 1, characterized in that, The inlet and outlet pipelines are connected by a peristaltic pump to achieve continuous feeding and discharging.

5. The microwave continuous flow reactor as described in claim 1, characterized in that, A video monitoring probe is installed on the sidewall of the circular waveguide to observe the changes in the state of the internal materials in real time.

6. The microwave continuous flow reactor as described in claim 1, characterized in that, Multiple thermometers are installed at different positions on the sidewall of the circular waveguide.

7. The microwave continuous flow reactor as described in claim 1, characterized in that, The continuous flow reactor is a spiral quartz coil structure consisting of a single quartz tube spirally wound and placed inside a circular waveguide cavity. The two ends of the spiral quartz coil are connected to the inlet pipe and the outlet pipe, respectively.

8. The microwave continuous flow reactor as described in claim 7, characterized in that, The spiral quartz coil runs through the entire circular waveguide.

9. The microwave continuous flow reactor as described in claim 7, characterized in that, The spiral quartz coil structure has an outer diameter of 20mm, an inner diameter of 16mm, and the quartz tube is spirally coiled 10 times.

10. The microwave continuous flow reactor as described in claim 1, characterized in that, The microwave frequency of the microwave solid-state source radiator is 2450±25MHz.

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