CN112272425B - On-line microwave heating device on industrial site - Google Patents

Abstract

The invention discloses an industrial field online microwave heating device, which comprises an excitation cavity shell and a resonance cavity shell, wherein a resonance window is fixedly connected between the excitation cavity shell and the resonance cavity shell, the waveguide structures of an excitation cavity in the excitation cavity shell and a resonance cavity in the resonance cavity shell are the same, the excitation cavity is communicated with the resonance cavity through a microwave through window arranged on the resonance window, a through hole which is vertically intersected with the axis of the microwave through window is arranged on the resonance window and used for a material pipe to pass through, a movable tuning plate is arranged in the excitation cavity and fixedly connected with a push-pull rod, the push-pull rod is in sliding fit with the excitation cavity shell and extends out of the excitation cavity shell, a magnetron is arranged at the upper end of the excitation cavity shell, and an energy output head of the magnetron extends into the excitation cavity and is positioned between the tuning plate and the resonance window.

Description

On-line microwave heating device on industrial site

technical field

The invention relates to the field of microwave heating, in particular to an on-line microwave heating device in an industrial field.

Background technique

Microwave is a high-frequency electromagnetic wave, which is widely used in communication, kitchen appliances, scientific instruments and other fields. The principle of microwave heating is: when the material is in the microwave field, the polar molecules in the material change with the polarity of the alternating electromagnetic field. The friction occurs due to periodic changes, and the energy of the microwave field is converted into heat energy. The use of microwave heating technology mainly includes microwave ovens. The microwave oven is composed of power supply, magnetron, resonant cavity and other parts. The power supply provides high voltage to the magnetron. The magnetron continuously generates microwaves under the excitation of the power supply, and then passes through the waveguide system and is coupled to the magnetron. In the resonant cavity, at the bottom of the resonant cavity, there is a rotatable tray. When heating, the materials to be heated are loaded with non-metallic utensils and placed on the tray. The rotation of the tray makes the microwave energy evenly distributed on the materials. , thereby heating the material. On the basis of the original microwave oven, the heating material is used in combination with the digestion tank, and a new technology of the microwave digestion instrument is derived. The material in the digestion tank is heated, but this microwave digestion instrument has limitations. The purpose of the microwave digestion instrument is to heat large volumes of substances, in order to achieve simultaneous digestion of multiple samples to improve the efficiency of batch digestion. , and is equipped with many digestion tanks. This device is currently only used in the laboratory and can only be used as a single heating device. It is difficult to be integrated into the online analysis system of the industrial site as a module. In addition, the huge resonance of the microwave digestion instrument The intensity of the microwave field in the cavity is relatively small, and there will be a problem that the heating rate is relatively slow.

SUMMARY OF THE INVENTION

The purpose of the present invention is to aim at the deficiencies of the prior art, and to provide an on-line microwave heating device in an industrial field, which can be integrated into an on-line analysis system in an industrial field as a module. At the same time, it can realize rapid heating of materials and improve the heating speed of materials.

The technical scheme of the present invention is as follows: an on-line microwave heating device for an industrial field, comprising an excitation cavity shell and a resonant cavity shell, wherein a resonance window is fixedly connected between the excitation cavity shell and the resonant cavity shell, and the excitation cavity The excitation cavity in the housing and the resonant cavity in the resonant cavity housing have the same waveguide structure, the excitation cavity and the resonant cavity are communicated with the microwave passing window provided on the resonance window, and the resonance window is provided with a passage perpendicular to the axis of the microwave passing window. The through hole is used for the passage of the material pipe. A movable tuning plate is arranged in the excitation cavity, and the tuning board is fixedly connected with a push-pull rod, which is slidingly matched with the excitation cavity shell and extends out of the excitation cavity. The shell, a magnetron is installed on the upper end of the excitation cavity shell, and the energy output head of the magnetron extends into the excitation cavity and is located between the tuning plate and the resonance window.

The excitation cavity and the resonator are both rectangular waveguides with a rectangular cross-section, and the resonant window has a rectangular cross-section, or both the excitation cavity and the resonator are circular waveguides with a circular cross-section, and the resonant window has a circular cross-section. .

The lengths of the excitation cavity and the resonant cavity are both integral multiples of 0.5 times the wavelength of the guided wave.

Both the excitation cavity and the resonant cavity use a BJ32 rectangular waveguide.

The distance between the energy output head of the magnetron and the resonance window is an integer multiple of 1/4 of the guided wave wavelength.

The resonance window, the excitation cavity shell and the resonance cavity shell are fixed by welding.

The material pipe adopts a non-metallic pipe, and both ends of the material pipe are used to connect the material conveying pipeline of the industrial site.

An adjusting gasket is arranged between the magnetron and the outer wall of the excitation chamber shell.

The resonant window is provided with a hole for installing the sensing element.

The magnetron 1 adopts a water-cooled magnetron of 2450 MHz, and the power is 1000 watts.

The above technical solution is adopted: an on-line microwave heating device in an industrial field, comprising an excitation cavity shell and a resonant cavity shell, a resonance window is fixedly connected between the excitation cavity shell and the resonant cavity shell, and a resonance window is fixedly connected between the excitation cavity shell and the resonant cavity shell. The excitation cavity is the same as the waveguide structure of the resonant cavity in the resonant cavity shell, the excitation cavity and the resonant cavity are communicated with the microwave passing window set on the resonance window, and the resonance window is provided with a through hole perpendicular to the axis of the microwave passing window, The through hole is used for the passage of the material pipe. A movable tuning plate is arranged in the excitation chamber. The tuning plate is fixedly connected with a push-pull rod, which is slidingly matched with the excitation chamber housing and extends out of the excitation chamber housing. , a magnetron is installed on the upper end of the excitation cavity shell, and the energy output head of the magnetron extends into the excitation cavity and is located between the tuning plate and the resonance window. During the heating operation, the energy output head of the magnetron excites an electromagnetic field in the excitation cavity. By adjusting the tuning plate and replacing the gaskets with different thicknesses, the electromagnetic field of the excitation cavity bypasses the resonance window and is coupled to the resonance cavity by electromagnetic diffraction. Internal resonance forms a super strong electromagnetic field distribution. At this time, the microwave transmission achieves impedance matching, and a strong magnetic field and a strong electric field are formed in the microwave passing window area of the resonance window. heating.

The excitation cavity and the resonator are both rectangular waveguides with a rectangular cross-section, and the resonant window has a rectangular cross-section, or both the excitation cavity and the resonator are circular waveguides with a circular cross-section, and the resonant window has a circular cross-section. . The shape of the resonant window can be matched according to the excitation cavity and the resonant cavity, which is convenient for flexible setting.

The lengths of the excitation cavity and the resonant cavity are both integral multiples of 0.5 times the wavelength of the guided wave, which facilitates the microwave transmission to more easily achieve impedance matching and enables better utilization of microwave energy.

Both the excitation cavity and the resonant cavity use a BJ32 rectangular waveguide, which is convenient for transmitting microwaves of 2450 MHz.

The distance between the energy output head of the magnetron and the resonance window is an integer multiple of 1/4 of the guided wave wavelength, which facilitates adjustment of microwave transmission to achieve impedance matching and maximizes microwave energy efficiency.

The resonance window, the excitation cavity shell and the resonance cavity shell are fixed by welding, which increases the firmness and sealing of the device and improves the transmission efficiency of microwaves.

The material pipe adopts a non-metallic pipe, and the two ends of the material pipe are used to connect the material conveying pipeline of the industrial site, so as to facilitate the integration of the device into the on-line analysis system of the industrial site.

There is an adjusting gasket between the magnetron and the outer wall of the excitation cavity shell. The adjusting gasket can change the depth of the magnetron's energy output head inserted into the excitation cavity shell, which is convenient to adjust the transmission of microwave energy and the magnetron. working status.

The resonance window is provided with a hole for installing the sensing element, which can be installed with the sensing element, which is convenient for monitoring the heating and heating state in the material pipe.

The magnetron adopts a 2450MHz water-cooled magnetron with a power of 1000 watts. The wavelength of the microwave emitted by it is shorter, and the microwave energy is easier to concentrate.

The on-line microwave heating device in the industrial field is simple in structure, small in size and easy to operate. It can be integrated into the on-line analysis system of the industrial field as a module. It can realize the rapid heating of the material in the material tube and improve the heating efficiency of the microwave.

The present invention will be further described below with reference to the accompanying drawings and specific embodiments of the description.

Description of drawings

Fig. 1 is the structural representation of the present invention;

Fig. 2 is a sectional view of the present invention;

Fig. 3 is the enlarged schematic diagram of the resonance window in Fig. 1;

FIG. 4 is a cross-sectional view taken along the line A-A in FIG. 2 .

Detailed ways

1 to 4, an industrial field online microwave heating device includes an excitation cavity shell 2 and a resonant cavity shell 6. One end of the excitation cavity shell 2 is open, and the other end is closed. A resonant window 5 is welded and fixed between the cavity shell 2 and the resonant cavity shell 6. The excitation cavity 2-1 in the excitation cavity shell 2 and the resonant cavity 6-1 in the resonant cavity shell 6 have the same waveguide structure , both rectangular waveguides or circular waveguides can be used at the same time, BJ32 rectangular waveguide is the best, the lengths of the excitation cavity 2-1 and the resonator cavity 6-1 are both integer times of 0.5 times the guided wave wavelength, so that the microwave energy can be obtained better use. The shape of the resonance window 5 can be set according to the shapes of the excitation cavity 2 and the resonance cavity 6. When the excitation cavity 2-1 and the resonance cavity 6-1 are both rectangular waveguides, the cross section of the resonance window 5 is rectangular. , or when the excitation cavity 2-1 and the resonant cavity 6-1 are both circular waveguides with a circular cross-section, the cross-section of the resonant window 5 is circular. The excitation cavity 2-1 is communicated with the resonant cavity 6-1 through the microwave passing window 5-1 provided on the resonant window 5, and the shape of the window 5-1 can be any shape such as a circle, a rectangle, an irregular figure, etc. The resonance window 5 is provided with a through hole 5-2 perpendicular to the axis of the microwave passing window 5-1. The through hole 5-2 is used for the passage of the material pipe 5-4, and the material pipe 5-4 adopts a non-metallic pipe. , the two ends of the material pipes 5-4 are provided with quick joints for connecting the material conveying pipelines on the industrial site, so that the device can be easily integrated into the on-line analysis system on the industrial site. The resonant window 5 is provided with a hole 5-3, which is used for installing a sensing element to monitor the heating and heating state in the material pipe 5-4. A movable tuning plate 3 is arranged in the excitation cavity 2, and the tuning board 3 is fixedly connected with a push-pull rod 3-1, the push-pull rod 3-1 slidingly fits with the excitation cavity shell 2 and extends out of the excitation cavity shell 2. A 2450MHz water-cooled magnetron 1 is installed on the outer wall of the upper end of the excitation cavity shell 2, and its working power is 1000 watts. The energy output head of the magnetron 1 extends into the excitation cavity 2-1, and is located in the excitation cavity 2-1. Between the tuning plate 3 and the resonance window 5, the distance between the energy output head of the magnetron 1 and the resonance window 5 is an integer multiple of 1/4 of the guided wave wavelength, and the magnetron 1 and the excitation cavity shell 2 There is an adjusting gasket 4 between the outer walls of the magnetron 1. The adjusting gasket 4 can change the depth at which the energy output head of the magnetron 1 is inserted into the excitation cavity shell 2, and is convenient to adjust the transmission of microwave energy and the working state of the magnetron.

When the on-line microwave heating device in the industrial site performs microwave heating, the two ends of the material pipe 5-4 in the through hole 5-2 of the resonance window 5 are connected to the material conveying pipe of the industrial site, so that the liquid material to be heated flows into the material pipe 5 In -4, then turn on the magnetron power supply to supply power to the magnetron 1, and the magnetron power supply provides the magnetron 1 with an anode voltage of 4.4kv, an anode current of 0.32A and a filament current of 3.15 volts, so that the magnetron 1 Working in the π mode, the TEM mode microwave field is generated in the energy output head of the magnetron 1, and then the electromagnetic field of the TE mode or the TM mode is excited in the excitation cavity 2, and then the tuning plate 3 is adjusted and the pads of different thicknesses are replaced. Sheet 4, when the measured value of the electrical parameters of the magnetron 1 matches or is close to the working characteristic curve provided by the magnetron manufacturer, the TE mode electromagnetic field of the excitation cavity 2 will bypass the resonant window 5 coupling by electromagnetic diffraction into the resonant cavity 6, and form a strong magnetic field and a strong electric field distribution in the area of the through hole 5-3 of the resonant window 5, so that the strong magnetic field and the strong electric field act together on the material pipe 5-4, and then realize the material pipe 5-4. 4 Rapid heating of the material in it.

Claims (10)

1. An on-line microwave heating device for an industrial site, characterized in that it comprises an excitation cavity shell (2) and a resonant cavity shell (6), wherein the excitation cavity shell (2) and the resonance cavity shell (6) are between the excitation cavity shell (2) and the resonance cavity shell (6). A resonant window (5) is fixedly connected between the two, the excitation cavity (2-1) in the excitation cavity shell (2) and the resonant cavity (6-1) in the resonant cavity shell (6) have the same waveguide structure, The excitation cavity (2-1) is communicated with the resonance cavity (6-1) through a microwave passing window (5-1) provided on the resonance window (5), and the resonance window (5) is provided with a microwave passing window (5). -1) A through hole (5-2) whose axis intersects vertically, the through hole (5-2) is used for the passage of the material pipe (5-4), and a movable tuning plate is arranged in the excitation cavity (2) (3), the tuning plate (3) is fixedly connected with a push-pull rod (3-1), the push-pull rod (3-1) is slidingly matched with the excitation cavity shell (2) and extends out of the excitation cavity shell (2) , a magnetron (1) is installed on the upper end of the excitation cavity shell (2), and the energy output head of the magnetron (1) extends into the excitation cavity (2-1), and is located between the tuning plate (3) and the between the resonant windows (5). 2 . The on-line microwave heating device for industrial sites according to claim 1 , wherein the excitation cavity ( 2 - 1 ) and the resonator cavity ( 6 - 1 ) are both rectangular waveguides with a rectangular cross section, and the The cross-section of the resonance window (5) is rectangular, or the excitation cavity (2-1) and the resonance cavity (6-1) are both circular waveguides with a circular cross-section, and the cross-section of the resonance window (5) is circular. 3. An industrial field online microwave heating device according to claim 1 or 2, characterized in that: the lengths of the excitation cavity (2-1) and the resonant cavity (6-1) are both 0.5 times the guided wave wavelength integer multiples of . 4 . The on-line microwave heating device for industrial sites according to claim 2 , wherein the excitation cavity ( 2 - 1 ) and the resonator cavity ( 6 - 1 ) both adopt BJ32 rectangular waveguides. 5 . 5 . The on-line microwave heating device for industrial sites according to claim 1 , wherein the distance between the energy output head of the magnetron ( 1 ) and the resonance window ( 5 ) is 1/4 of the guided wave wavelength. 6 . integer multiples of . 6 . The on-line microwave heating device for industrial sites according to claim 1 , wherein the resonance window ( 5 ) is fixed to the excitation cavity shell ( 2 ) and the resonance cavity shell ( 6 ) by welding. 7 . 7. An on-line microwave heating device for an industrial site according to claim 1, characterized in that: the material pipe (5-4) adopts a non-metallic pipe, and both ends of the material pipe (5-4) are used for Connecting material conveying pipelines on industrial sites. 8. An on-line microwave heating device for industrial sites according to claim 1, characterized in that: an adjusting gasket (4) is provided between the magnetron (1) and the outer wall of the excitation cavity shell (2). . 9 . The on-line microwave heating device for industrial sites according to claim 1 , characterized in that: the resonance window ( 5 ) is provided with a hole ( 5 - 3 ) for installing a sensing element. 10 . 10 . The on-line microwave heating device for an industrial site according to claim 1 , wherein the magnetron ( 1 ) adopts a water-cooled magnetron of 2450 MHz, and its power is 1000 watts. 11 .

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