433 MHz Solid State Microwave Heating Cavity and Industrial Defrosting System

Abstract

The disclosure relates to 433 MHz solid state microwave heating cavity and industrial defrosting system. The 433 MHz solid state microwave heating cavity and industrial defrosting system includes a sample conveying device, a metal detector, a microwave processing system, and a motor, provided on a machine frame. An upper part and a bottom part of a microwave processing module are provided with a microwave source separately. Microwave sources are connected to bell mouths through wave guide tubes. Two bell mouths are connected to a heating cavity through microwave windows. The microwave source is a 433 MHz solid-state microwave source. The high-power-density 433 MHz microwave is used to penetrate meat products to make a uniform temperature inside and outside after defrosting, the defrosting takes only 2-4 minutes from 18 C. to 2 C., color and nutrients of the meat products after the defrosting are basically the same as those of fresh meat.

Claims

1. 433 MHz solid state microwave heating cavity and industrial defrosting system, comprising: a sample conveying device, a metal detector, a microwave processing system, and a motor, provided on a machine frame, wherein the motor is connected to the sample conveying device through a cable; the sample conveying device is a non-metallic conveying device, passes through the microwave processing system, and runs from the metal detector to a direction of the microwave processing system; the metal detector is provided at a feeding end of the sample conveying device; the microwave processing system is arranged behind the metal detector, the microwave processing system comprises two or more microwave processing modules connected in sequence, and each of the microwave processing modules has complementary heat types; an upper part and a bottom part of each of the microwave processing modules are provided with a microwave source separately, microwave sources are connected to bell mouths of the microwave processing module through wave guide tubes, and an upper bell mouth of the bell mouths and a lower bell mouth of the bell mouths are connected to a heating cavity in a middle of the microwave processing module through microwave windows, respectively; the microwave source is a 433 MHz solid-state microwave source; and a side surface of the heating cavity is provided with a reflecting surface adjusting device, the reflecting surface adjusting device comprises a metal inner plate, a screw rod and a scissor adjusting mechanism, both ends of the scissor adjusting mechanism are fixedly connected to the inner plate and a metal plate on a side surface of the heating cavity, respectively, the screw rod passes through the metal plate, and an end of the screw rod is provided with a handle.

2. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 1, wherein the sample conveying device comprises gears provided on both sides of the machine frame, and a chain conveyor belt mounted on the gears, the chain conveyor belt is made of a non-metallic material, a bottom part of the chain conveyor belt is provided with a support member made of a non-metallic material, the support member is configured to adjust a tightness and/or relaxation of the chain conveyor belt to keep the chain conveyor belt running stably.

3. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 1, wherein a discharging end of the sample conveying device is provided with an infrared temperature measuring instrument.

4. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 3, wherein the machine frame is further provided with a control system, the control system comprises a PLC and a touch screen connected to the PLC, and the PLC controls the sample conveying device, the metal detector, the microwave processing system, the infrared temperature measuring instrument, and the motor through the cable.

5. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 1, wherein the microwave window is one of a flat plate shape, a solid cylindrical shape, a convex lens, and a concave lens to achieve microwave concentration or scattering.

6. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 1, wherein a height of the heating cavity is 30-60 cm; and a width of the heating cavity is 30-60 cm.

7. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 1, wherein both a feeding end and a discharging end of the sample conveying device are provided with a microwave suppressor.

8. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 1, wherein a microwave power of the microwave processing module is greater than or equal to 20 KW.

9. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 1, wherein a width of each of the wave guide tubes is 533.4 mm; and a height of each of the wave guide tubes is 266.7 mm.

10. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 4, wherein the 433 MHz solid-state microwave source is electrically connected to the PLC, and a working state of the 433 MHz solid-state microwave source is adjusted through the touch screen; the 433 MHz solid-state microwave source is capable of calculating an intensity of a reflected wave and acquiring corresponding dielectric characteristic parameter information according to the intensity of the reflected wave; and the 433 MHz solid-state microwave source acquires the dielectric characteristic parameter information in real time, and determines a defrosting state of current food according to a change of the dielectric characteristic parameter information.

11. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 10, wherein the touch screen is capable of displaying the following information: species of food, the intensity of the reflected wave, reflected power, real-time dielectric characteristic parameter information, and the defrosting state.

12. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 10, wherein the PLC adjusts the heating power of the 433 MHz solid-state microwave source corresponding to next microwave processing module according to the defrosting state of the current food, so as to achieve uniform defrosting of the food while saving energy.

13. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 10, wherein there are two or more heating cavities, the PLC adjusts the heating power of the 433 MHz solid-state microwave source corresponding to next microwave processing module according to the defrosting state of the current food, so as to realize the complementary heat type of each microwave processing module and achieve a purpose of defrosting different foods uniformly.

14. The 433 MHz solid state microwave heating cavity and industrial defrosting system as claimed in claim 1, wherein there are a plurality of reflecting surface adjusting devices, each of heating cavities is provided with two reflecting surface adjusting devices, the two reflecting surface adjusting devices in the same heating cavity are respectively provided on both sides of the sample conveying device, a space between two inner plates of the two reflecting surface adjusting devices is a space through which food passes, a distance between the two inner plates is adjusted to adjust an electric field distribution, and each of the inner plates is adjustable independently.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the disclosure or the technical solutions in the conventional art, the drawings used in the description of the embodiments or the conventional art will be briefly described below. It is apparent that the drawings in the following description are only some embodiments of the disclosure, and other drawings can be obtained from those skilled in the art according to these drawings without any creative work.

[0045] FIG. 1 is a schematic structure diagram of the disclosure.

[0046] FIG. 2 is a top view of the disclosure.

[0047] FIG. 3 is a schematic structure diagram of a microwave processing module.

[0048] FIG. 4 is a schematic structure diagram of a flat-plate microwave window.

[0049] FIG. 5 is a schematic structure diagram of a solid-cylindrical microwave window.

[0050] FIG. 6 is a schematic cross-sectional structure diagram of a reflecting surface adjusting device.

[0051] FIG. 7A-FIG. 7C is an electric field distribution diagram.

[0052] FIG. 8 is a schematic diagram of electric field complementation (a shaded part is a cold point, the other part is a hot point, and as the shadow density is larger, the temperature is lower).

[0053] In the drawings, 1: machine frame, 2: sample conveying device, 21: gear, 22: chain conveyor belt, 3: metal detector, 4: microwave processing module, 41: microwave source, 42: wave guide tube, 43: bell mouth, 44: microwave window, 45: heating cavity, 451: inner plate, 452: screw rod, 453: scissor adjusting mechanism, 454: handle, 46: metal plate, 5: motor, 6: control system, 7: infrared temperature measuring instrument, a: heating cavity, b: heating cavity, c: heat type passing through heating cavity a and heating cavity b, 8: front-end channel cover, 9: middle connecting cover, 10: rear-end channel cover.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0054] In order to make the objectives, technical solutions and advantages of the embodiments of the disclosure clearer, the technical solutions in the embodiments of the disclosure will be clearly and completely described hereinbelow with the drawings in the embodiments of the disclosure. It is apparent that the described embodiments are part of the embodiments of the disclosure, not all of the embodiments. On the basis of the embodiments of the disclosure, all other embodiments obtained on the premise of no creative work of those of ordinary skill in the art fall within the scope of protection of the disclosure.

Embodiment 1

[0055] As shown in FIG. 1 and FIG. 2, 433 MHz solid state microwave heating cavity and industrial defrosting system includes a sample conveying device 2, a metal detector 3, a microwave processing system, and a motor 5, provided on a machine frame 1.

[0056] The motor 5 is connected to the sample conveying device 2 through a cable and supplies power thereto. The sample conveying device 2 is a non-metallic conveying device, passes through the microwave processing system, and runs from the metal detector 3 to a direction of a rear end.

[0057] The metal detector 3 is provided on one side of a feeding end of a conveyor belt, and can detect metal-containing materials. After generating an alarm, manual screening is performed to screen out the metal-containing materials at a feeding inlet to avoid metal substances from entering the microwave processing system. If there is a small volume of metal, microwaves will enter from the surrounding of the metal. The temperature of the surrounding area of the metal is too high, the temperature difference is large, and the quality is degraded. The larger metal will cause microwave shielding and cannot implement defrosting. The microwave processing system is arranged behind the metal detector, and includes two or more microwave processing modules 4 connected in sequence, which may be optimally combined according to different requirements to obtain better heating uniformity. The modular design of microwave heating cavity is adopted, that is, there are multiple microwave heating cavities, different parameter settings can make the heating type of each heating cavity different, FIG. 7A-FIG. 7C is taken as an example, that is, in the actual electric field distribution, and when a material continuously passes through the first heating cavity and a second heating cavity, due to the different energy distribution, the heat type complementary effect can be achieved. FIG. 8 is taken as an example. If the energy of the heating cavity a is concentrated in the middle, that is, the middle is a hot point area, the energy of the heating cavity b is concentrated around, after passing through the two microwave heating cavities, the temperature difference between the cold and hot points will be reduced, and better uniformity can be achieved.

[0058] As shown in FIG. 2, two microwave processors 7 are provided at an interval. The 433 MHz solid state microwave heating cavity and industrial defrosting system includes a front-end channel cover 8, a middle connecting cover 9 and a rear-end channel cover 10. The front-end channel cover 8 is connected to an inlet end of right microwave processor 7 in FIG. 1 and extends forward for a distance. The rear-end channel cover 10 is connected to an outlet end of the left microwave processor 7 in FIG. 1 and extends backward for a distance. The middle connecting cover 9 is connected between the inlet end of the left microwave processor 7 and the outlet end of the right microwave processor 7, so that the front-end channel cover 8, the middle connecting cover 9, the rear-end channel cover 10 and the two heating cavities form a complete heating channel through which food passes, while preventing the heat of microwave radiation from escaping, improving energy efficiency and avoiding radiation.

[0059] As shown in FIG. 3, an upper part and a bottom part of the microwave processing module 4 are provided with a microwave source 41 separately, the microwave sources 41 are connected to bell mouths 43 through wave guide tubes 42, the bell mouths are configured to evenly disperse the microwave, it can be designed in advance according to the type and size of defrosted products, and the components can be replaced later as needed to ensure the uniformity of heating. The upper and lower bell mouths are connected to central heating cavity 45 through the microwave windows 44, respectively, the microwave enters the heating cavity through the microwave window, and the microwave window can also prevent water vapor and dust from entering the instrument. The microwave source is a 433 MHz solid-state microwave source. As shown in FIG. 6, a side surface of the heating cavity is provided with a reflecting surface adjusting device, including a metal inner plate 451, a screw rod 452 and a scissor adjusting mechanism 453, both ends of the scissor adjusting mechanism 453 are fixedly connected to the inner plate 451 and a metal plate 46 on the side surface of the heating cavity, respectively, the screw rod passes through the metal plate, and an end is a handle 454. The handle is rotated to adjust the length of the screw rod in the heating cavity, thereby adjusting the position of the inner plate and adjusting the width of the heating cavity, so as to adjust the electric field distribution according to the actual situation to ensure the uniformity of heating. The 433 MHz wavelength is very long, the screw rod and the hole are in screw thread contact and no gap, which can prevent the microwave from leaking out.

[0060] The sample conveying device 2 includes gears 21 provided on both sides of the machine frame, and a chain conveyor belt mounted on the gears, the chain conveyor belt is made of a non-metallic material, for example but not limited to, a plastic material, and a bottom part of the chain conveyor belt is provided with a support member made of a non-metallic material. Further, the support member has a T-shaped structure, which is used to support the chain conveyor belt to adjust the degree of tightness and/or relaxation of the chain conveyor belt, so as to keep the chain plate conveyor belt running stably.

[0061] A discharging end of the sample conveying device is provided with an infrared temperature measuring instrument 7, capable of measuring the surface temperature of a sample in real time, and monitoring a defrosting situation.

[0062] The machine frame is further provided with a control system 6, including a PLC and a touch screen connected to the PLC, and the PLC controls the sample conveying device 2, the metal detector 3, the microwave processing system 4, the infrared temperature measuring instrument 7, and the motor 5 through the cable. The touch screen is used to operate the computer, set the operation, alarm, prompt and other instructions, establish a defrosting material process package database, perform related processes according to different materials, and set a function of automatic defrosting with materials and automatic standby without materials.

[0063] As shown in FIG. 4, the microwave window is a flat plate shape, and the flat plate shape is a commonly used microwave window, which is convenient to manufacture. The microwave window of the heating cavity may be designed in different shapes, for flat windows, hemispherical or lenticular (convex or concave lenses) converging or dispersing, to adjust the electric field distribution and the temperature distribution inside the material.

[0064] The front and rear ends of the microwave processing system are open for the sample conveying device to pass through, both the feeding end and the discharging end of the sample conveying device are provided with a microwave suppressor, the microwave suppressor includes a reflecting part and an absorbing part, the reflecting part is usually metal of an irregular shape, and the absorbing part is usually a graphene or silicon carbide plate, which is used to absorb the reflected microwave. The microwave suppressor currently on the market can be used. For the specific structure, reference may be made to patent 201310631185.1 Microwave Suppressor and Tunnel Microwave Heating System and 2018212792024 Archipelago Microwave Suppressor. The test results show that the microwave leakage during the microwave operation of the disclosure is generally 1-2.5 mW/cm.sup.2.

[0065] In the present embodiment, the 433 MHz solid-state microwave source is electrically connected to the PLC, and a working state of the 433 MHz solid-state microwave source is adjusted through the touch screen. The 433 MHz solid-state microwave source is capable of calculating the intensity of a reflected wave and acquiring corresponding dielectric characteristic parameter information according to the intensity of the reflected wave. The 433 MHz solid-state microwave source acquires dielectric characteristic parameter information in real time, and determines a defrosting state of current food according to the change of the dielectric characteristic parameter information. The equipment can analyze changes in the dielectric properties of defrosted foods by calculating the intensity of reflected waves (reflected power). Due to the phase change before and after defrosting, the dielectric properties of food are changed significantly, and when the dielectric characteristic value reaches a certain range, the corresponding defrosting situation is determined.

[0066] Specifically, the touch screen is capable of displaying the following information: species of food, intensity of the reflected wave, reflected power, real-time dielectric characteristic parameter information, and the defrosting state.

[0067] In the present embodiment, the PLC adjusts the heating power of the 433 MHz solid-state microwave source corresponding to the next microwave processing module according to the defrosting state of the current food, so as to achieve heat type complementation of each microwave processing module. The control system may automatically adjust the power of the heating cavity to be passed, the adjusting power can be automatically matched for the material that is being defrosted, the defrosting time is shortened, the temperature difference between cold and hot points is reduced, and the defrosting temperature of the same batch is more uniform.

[0068] In an exemplary embodiment, there are two or more heating cavities, so as to realize the complementary heat type of each microwave processing module and achieve the purpose of defrosting different foods uniformly.

[0069] There are multiple reflecting surface adjusting devices, each of the heating cavities is provided with two reflecting surface adjusting devices, the two reflecting surface adjusting devices in the same heating cavity are respectively provided on both sides of the sample conveying device, the space between the two inner plates of the two reflecting surface adjusting devices is the space through which food passes, and a distance between the two inner plates is adjusted to adjust an electric field distribution. Equipment is suitable for multiple materials.

Embodiment 2

[0070] As shown in FIG. 5, the microwave window is a solid cylindrical shape. The solid cylindrical type can better focus the microwave.

[0071] The height of the heating cavity is 30-60 cm and the width is 30-60 cm, which is suitable for the defrosting of various meat standard packages (30 cm*60 cm*20 cm) and different shapes and sizes of meat and seafood.

[0072] The rest are the same as in Embodiment 1.

Embodiment 3

[0073] The microwave power of the microwave processing module is greater than or equal to 20 KW. The wave guide tube selects the national standard BJ4, and has a width of 533.4 mm and a height of 266.7 mm.

[0074] The rest are the same as in Embodiment 1.

Embodiment 4

[0075] The reflecting surface adjusting device is different from that in Embodiment 1. Specifically, the reflecting surface adjusting device includes a metal inner plate, a servo motor and a scissor adjusting mechanism. Both ends of the scissor adjusting mechanism are fixedly connected to the inner plate and the metal plate on the side surface of the heating cavity to ensure no leakage during microwave conveying.

[0076] The device is applied to the defrosting of various meat standard packages (30 cm*60 cm*20 cm) and meat and seafood of different shapes and sizes. The material can be returned to the temperature range of 4 C. to 2 C. . Meat standard packages (30 cm*60 cm*20 cm, with plastic packaging films) are included: duck meat, beef quarters, beef tenths, pork sixths, lamb, etc.; irregular shapes and sizes of food: lamb legs, whole chickens, ducks, livestock, poultry, etc.; aquatic products: fish slip, shrimp slip, surimi, frozen shrimp, etc. According to different objects, different sizes of the bell mouth, the size and type of the microwave window and the width of the heating cavity can be designed. When changing the defrosted object, only the corresponding size parts need to be replaced according to the object. The entire production cable does not need large-scale reconstruction, which greatly improves the flexibility of use and saves a lot of costs.

[0077] The defrosting process is as follows: a material is placed on a food carrier, a meat standard block or a sample to be defrosted is placed on a feeding end of a conveyor belt, after a metal detector passes the test, the conveyor belt runs automatically, a target defrosting temperature is reached by microwave processing of a microwave heating cavity, after an infrared temperature measuring instrument measures the temperature, the material is discharged from a discharging end, and quick non-destructive defrosting is realized.