KR100727314B1 - Thawing apparatus using microwave - Google Patents

Abstract

A thawing apparatus using a microwave is provided to uniformly thaw frozen food within a short time regardless of a size of the frozen food by using a single magnetron which oscillates the microwave of 915Mhz. A thawing apparatus using a microwave includes a thawing room(20), a microwave generation chamber(40), a waveguide structure(30), a matching unit(60), and a controller. The thawing room(20) has a turntable to put frozen food thereon. The microwave generation chamber(40) is installed at one side of the thawing room(20), and has a magnetron which oscillates the microwave. The waveguide structure(30) is installed in the thawing room(20) to irradiate the microwave generated in the microwave generation chamber(40) to the inside of the thawing room(20). The waveguide structure(30) detects and absorbs a reflective wave which is reflected from the frozen food. The matching unit(60) is installed between the thawing room(20) and the waveguide structure(30) to reduce the reflective wave which is reflected from the frozen food, and matches the frozen food with the waveguide structure(30). The controller controls the matching unit(60) according to a quantity of the reflective wave detected in the waveguide structure(30).

Description

Thawing apparatus using microwaves {THAWING APPARATUS USING MICROWAVE}

1 is a front view showing a thawing apparatus using a microwave according to an embodiment of the present invention,

2 is a plan view showing a thawing apparatus using a microwave according to an embodiment of the present invention,

3 is a perspective view showing a matching means according to an embodiment of the present invention,

Figure 4 is a schematic view showing a magnetron and a launcher according to an embodiment of the present invention,

5 is a block diagram showing a power converter according to an embodiment of the present invention,

6 is a frequency waveform of the positive voltage detected by the divider according to the embodiment of the present invention.

♠ Explanation of symbols for the main parts of the drawing ♠

1 controller 3 display unit

10: thawing apparatus 20: thawing chamber

30: waveguide structure 40: microwave generating chamber

41: magnetron 50: power converter

60: matching means

The present invention relates to a thawing apparatus using microwaves for thawing frozen foods by irradiating microwaves to frozen foods, and more particularly, frozen foods and microwaves by matching waveguides irradiated with microwaves to penetrate microwaves to the inside of frozen foods. It relates to a thawing apparatus using a microwave capable of thawing to 0 ℃ ~ -5 ℃.

In general, the method of thawing frozen foods that have been quenched (frozen at -20 degrees or -40 degrees or below) in units of several kilograms to several tens of kilograms can be used to defrost frozen foods at room temperature. There are water immersion thawing in the storage, microwave thawing method such as microwave oven to thaw.

At present, the most common method of thawing frozen foods that have been quenched is a method of naturally thawing by storing the frozen foods for a long time (2 to 5 days) in a large refrigerator. However, the thawing method using the cold storage is difficult to carry out frozen food at the required time due to the long thawing time, and also has to secure a certain amount of inventory at all times and have a large cold storage. have.

Therefore, in recent years, the thawing method using microwave is gradually increasing. The thawing method using microwaves is to thaw frozen products by installing multiple magnetrons with 2450MHz microwaves to oscillate microwaves into frozen food. Microwaves of 2450MHz are suitable for small frozen foods because they have a short wavelength and are well suited for the natural frequency of water molecules and the penetration depth of food foam is about 5 ~ 7cm from the surface.

In other words, the thawing apparatus using a magnetron that generates 2450 MHz microwaves, when the size of frozen food is large, for example, when thawing frozen food in units of several kilograms to several tens of kilograms, only the surface of the frozen food is thawed and the inside is not thawed. As a result, the problem that frozen foods are not evenly thawed occurs frequently. In addition, since 2450 MHz microwaves are oscillated in a plurality of magnetrons, interference occurs between the magnetrons, and the microwaves oscillated in the magnetrons are distorted and the lifespan of the magnetrons is reduced.

The present invention was created in order to solve various problems of the prior art as described above, and an object of the present invention is to uniformly use frozen foods within a short time regardless of the size of frozen foods using a single magnetron in which microwaves of 915 MHz are oscillated. It is to provide a thawing apparatus using a microwave that can be thawed.

Another object of the present invention is to provide a thawing apparatus using microwaves that can prevent the magnetron from being broken by preventing the reflected wave generated when thawing frozen foods to be delivered to the magnetron.

Defrosting apparatus using a microwave according to the present invention for achieving the above object comprises a thawing chamber in which a turntable is built to raise frozen food therein; A microwave generating chamber provided at one side of the thawing chamber and having a magnetron inside which the microwave is oscillated; A waveguide structure having one end mounted in the thawing chamber and the other end mounted in the microwave generating chamber so that microwaves generated by the microwave generating chamber are irradiated into the thawing chamber; Matching means provided between the thawing chamber and the waveguide so as to reduce the reflected wave reflected from the thawing chamber to match the thawing chamber with the waveguide; And a controller for controlling the matching means by sensing the reflected wave reflected after the microwave is irradiated to the frozen food.

Hereinafter, a preferred embodiment of a thawing apparatus using a microwave according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2, the thawing apparatus 10 is provided with a thawing chamber 20 in which frozen food is incorporated. The thawing chamber 20 has a predetermined space therein, and one side is provided with a door 21 to inject frozen food, and the other side of the thawing chamber 20 allows microwaves to be irradiated through the waveguide structure 30. An opening 20a to which the 30 is connected is formed. Frozen food is placed inside the thawing chamber 20, and a turntable 23 is rotated by the motor 23a.

And the thawing chamber 20 is further provided with a shielding plate 25 to prevent leakage to the outside of the microwave thawing chamber 20 oscillated into the interior of the thawing chamber 20, one side of the shielding plate 25 The reflector 27 is mounted so that microwaves can be uniformly distributed in the thawing chamber 20. The reflecting plate 27 is rotated by the motor 27a. On the other hand, the door 21 is formed with a see-through window 21a so that the inside of the thawing chamber 20 can be seen, and the see-through window 21a has a screen net form. The production of the see-through window 21a in the form of a screen net is for preventing microwaves from leaking out of the thawing chamber 20 through the see-through window 21a. In the interior of the thawing room 20, the illumination 29 and the infrared temperature sensor 20b for sensing the temperature of the frozen food so as to more clearly check the thawing degree of the frozen food through the viewing window 21a, A detection sensor 20c is further provided to detect the frozen food placed on the turntable 23.

The thawing apparatus 10 further includes a microwave generating chamber 40 spaced apart from the thawing chamber 20 by a predetermined interval. Inside the microwave generating chamber 40, a magnetron 41 for generating microwaves is provided. Magnetron 41 of the present embodiment is used 30Kw or more capable of oscillating microwave of 915Mhz so that the oscillated microwave is completely transmitted to the inside of the frozen food. On the other hand, the microwave generating chamber 40 is further provided with a power converter 50 for stable power supply to the magnetron 41, which will be described later.

The thawing chamber 20 and the microwave generating chamber 40 are connected by the waveguide structure 30 so that microwaves are irradiated into the thawing chamber 20. The waveguide structure 30 is provided with a direction coupler 31, a circulator 33, and a stub tuner 35 at the center thereof, and a microwave generator 40. By a Launcher 37).

The direction coupler 31 detects the reflected wave of the microwave irradiated to the thawing chamber 20 and has a reflected wave sensor 31a capable of detecting the reflected wave.

On one side of the circulator 33, a water rod 39 is attached to absorb the reflected wave and discharge it to the outside, and the water rod 39 has water in which the reflected wave is absorbed to convert the reflected wave into heat. . The stub tuner 35 is equipped with four stubs 35a and adjusts the depth of the stub 35a so that the microwaves weakened by the reflected waves are well transmitted to the frozen food.

The launcher 37 prevents the magnetron 41 from being damaged by the reflected wave not absorbed by the circulator 33. To this end, as shown in FIG. 4, the launcher 37 includes a first sensing sensor 37a capable of sensing a temperature of the magnetron 41 and a second arc capable of sensing an arc generated from the magnetron 41. The detection sensor 37b is attached. When the temperature of the magnetron 41 antenna exceeds 200 ° C., the first detection sensor 37a sends a signal to the controller 1 by detecting the temperature of the magnetron 41 antenna, and the controller 1 receiving the signal transmits the power of the power converter 50. Stop the operation of the magnetron (41).

Meanwhile, the controller 1 of the thawing apparatus 10 detects a signal input from each of the sensors 20b, 20c, 31a, 37a, and 37b to control the power converter 50 and matching means 60 to be described later. do.

Referring to FIG. 3, a matching means 60 is provided between the waveguide structure 30 and the thawing chamber 20 so as to match the frozen food and the waveguide structure 30. The matching means 60 is a cavity 61 in which an opening 61a is formed so that microwaves can proceed in the center, and an upper portion of the cavity 61 so as to open and close the opening 61a of the cavity 61. And a pair of sliding plates 63 and 65 that are slidably installed in the lower portion, an operating rod 67 for operating the sliding plates 63 and 65, and a motor 69 for rotating the operating rod 67, respectively. ) Each sliding plate 63, 65 is attached with brackets 63a, 65a into which one end and the other end of the operating rod 67 are inserted, respectively. One end and the other end of the operating rod 67 is formed to correspond to the screw so that the sliding plate (63, 65) in the opposite direction by the rotation of the operating rod 67 to open and close the opening (61a) It is.

When the operating rod 67 is rotated forward, the sliding plates 63 and 65 move toward each other, and the opening 61a is gradually closed. When the operating rod 67 is reversed, the sliding plates 63 and 65 are rotated. The opening 61a is gradually opened away. That is, the matching means 60 is the size of the opening (61a) by the sliding plate (63, 65) is adjusted to match the frozen food and the waveguide structure (30).

On the other hand, the motor 69 of the matching means 60 is rotated forward and backward by the controller (1), the reflection wave sensor 31a of the direction coupler 31 detects the intensity of the reflected wave first generated by the controller (1) and after a certain time has elapsed, it again detects the intensity of the reflected wave and sends the value to the controller (1). The controller (1) compares the first value with the next value and the motor (69) ) Is stopped, and when the initial value is large, the motor 69 is rotated. Then, the size of the opening 61a is adjusted by the sliding plates 63 and 65 to match the impedance of the frozen food and the waveguide structure 30. That is, by matching the frozen food and the waveguide structure 30, the strength of the reflected wave can be reduced to prevent the magnetron 41 and the power converter 50 from being damaged by the reflected wave.

Referring to FIG. 5, the power converter 50 includes a filament power supply unit 51, a magnetron anode power supply unit 53, an electromagnet power supply unit 55, and a divider 57, and the magnetron 41 may operate. A high voltage of 12OOOV or higher is applied to the magnetron 41 so that the magnetron 41 can be operated. The power converter 50 first applies a high voltage of 12000 V until microwaves are generated from the magnetron 41 so that surge voltage is not generated when a high voltage of 12000 V or more is applied, and after 5 seconds, until the rated voltage at which microwaves are generated. Secondly, a high voltage of 14000V is applied.

The filament power supply unit 51 supplies power to the filament (not shown) of the magnetron 41, and is further provided with a filament current detection unit 51a for detecting the current of the filament. The magnetron anode power source 53 supplies power to the magnetron 41 and further includes a cathode current detection unit 53a for sensing the anode current of the magnetron 41. The electromagnet power supply unit 55 supplies electric power to the electromagnet 43 provided on one side of the magnetron 41, and is further provided with an electromagnet current detection unit 55a for detecting the current of the electromagnet 43. The divider 57 is connected to a terminal of the filament power supply 51 and a terminal of the magnetron positive power supply 53, and detects a waveform of a voltage supplied to the magnetron 41. In the divider 57 according to the present embodiment, it is preferable to use a voltage detection ratio of the anode voltage detection ratio of the magnetron anode power supply portion 51: a voltage detection ratio of the magnetron anode power supply portion 53 is 1000: 1. The filament current detector 51a checks if 115A is supplied within 30 seconds of the filament current supplied to the initial magnetron for stable operation of the magnetron, and proceeds to the next operation.If the filament current does not reach 115A by 30 seconds, the equipment is stopped. The warning is displayed on the display unit 3. In addition, the filament current detection unit 51a prevents the filament of the magnetron from being damaged by reducing the filament current to 115A to 95A when the anode current increases from 0A to 2.4A compared to the anode current of the anode current detection unit. The anode current detection unit 53a reduces or decreases the electromagnet current to 4A to 2A so as to be equal to the set microwave power (0 to 30KW), and immediately shuts off the power supply of the anode power supply when the anode current is more than 2.8A to protect the magnetron. And display a warning on the display unit 3.

The electromagnet current detection unit 55a checks whether 4A is generated in the electromagnet within 30 seconds after the initial electromagnet power supply for stable operation of the magnetron, and proceeds to the next operation, and stops the equipment if the electromagnet current does not reach 4A by 30 seconds. And a warning is displayed on the display unit 3. In addition, if the microwave power is different from the microwave power value by checking whether the set is the same, the display unit 3 displays an electromagnet or magnetron or more.

The filament power supply unit 51 and the magnetron anode power supply unit 53 supply power to the magnetron 41 so that the magnetron 41 can operate stably. The filament power supply unit 51 supplies power so that the initial filament current of the magnetron 41 may gradually increase to 0A to 115A, and the magnetron anode power supply unit 53 may gradually increase the initial current of the electromagnet to 0A to 4A. Supply power. On the other hand, the positive voltage waveform detected by the divider 57 is displayed on the display unit 3. Referring to FIG. 6, when the magnetron 41 is normal, the waveform as shown in FIG. 6 (a) appears, and the magnetron 41 is shown. As the function of) decreases, the anode voltage waveform generated due to insufficient radiation current of the magnetron 41 as shown in FIGS. 6B to 6D is distorted, that is, a molding phenomenon occurs. The operator can check the anode voltage waveform displayed on the display unit 3 to know when to replace the magnetron 41.

In the thawing apparatus 10 according to the present embodiment, when the magnetron 41 operates to oscillate microwaves, much heat is generated in the magnetron 41, the water rod 10, the electromagnet 43, and the circulator 33. The magnetron 41, the water rod 10, the electromagnet 43 and the circulator 33 are cooled by water cooling.

Now, the operation of the thawing apparatus according to the present embodiment manufactured as described above will be described in detail.

First, after placing the frozen food to be thawed on the turntable 23 of the thawing chamber 20, and closing the door 21 of the thawing chamber 20, the frozen food sensor 20c is the edible food and the door Detects the closing of the 21 and sends a signal to the controller 1, the controller 1 operates the power converter 50 to supply power to the magnetron 41 to operate the magnetron 41 to operate the microwave do. Microwaves oscillated from the magnetron 41 are irradiated to the thawing chamber 20 along the waveguide structure 30 and transmitted to the frozen food rotated by the turntable 23. Microwaves irradiated to the thawing chamber 20 are diffracted and reflected by the rotating reflector 27 to be uniformly transmitted to all the portions of the frozen food, and the frozen food is thawed.

At this time, the microwave reflected wave reflected by the frozen food is returned to the waveguide structure 30 again. The reflected wave returned to the waveguide structure 30 is detected by the direction coupler 31, and the reflected wave sensor 31a detects the reflected wave amount and periodically applies a signal to the controller 1. Then, the controller 1 adjusts the size of the opening 61a of the cavity 61 by rotating the motor 69 of the matching means 60 according to the amount of reflected waves to match the frozen food and the waveguide structure 30. The circulator 33 absorbs the reflected wave into the water rod 39 and converts it into heat. In addition, by reducing the reflected wave generated by adjusting the stub (35a) of the stub tuner 35 to a minimum it is possible to improve the transmission efficiency of the microwave transmitted through the frozen food.

When the frozen food is thawed and the temperature of the frozen food is between 0 ° C. and −5 ° C., the infrared temperature sensor 20b provided in the thawing chamber 20 detects the temperature and sends a signal to the controller 1. The controller 1 cuts off the power of the power converter 50 to stop the operation of the magnetron 41 to complete the thawing of the frozen food.

In the above, preferred embodiments of the present invention have been described, but modifications and variations within the scope without departing from the technical spirit of the present invention by those skilled in the art belong to the scope of the present invention Of course.

As described above, according to the thawing apparatus using microwaves according to the present invention, since frozen foods are thawed using a single magnetron having a microwave of 915 MHz, frozen foods are packaged in a short time regardless of the size of the frozen foods. There is an effect that can be thawed uniformly.

In addition, since the matched frozen food and the waveguide structure are matched by the matching means and the reflected wave is absorbed by the circulator, the reflected wave transmitted to the magnetron is minimized, thereby preventing the magnetron from being damaged by the reflected wave.

Claims (7)

In the thawing apparatus using a microwave for thawing the frozen food by irradiating the microwave to the frozen food, A thawing chamber having a turntable embedded therein to place the frozen food therein; A microwave generating chamber provided at one side of the thawing chamber and having a magnetron inside which the microwave is oscillated; One end is mounted to the thawing chamber and the other end is mounted to the microwave generating chamber so that microwaves generated from the microwave generating chamber are irradiated into the thawing chamber, and a waveguide for detecting and absorbing reflected waves reflected from the frozen food. A structure; Matching means provided between the thawing chamber and the waveguide so as to reduce the reflected wave reflected from the frozen food and to match the frozen food and the waveguide; And a controller for controlling the matching means in accordance with the amount of the reflected wave detected by the waveguide structure. The method of claim 1, The matching means includes a cavity in which an opening is formed in the center to allow the microwaves to proceed, a pair of sliding plates that are slidably installed in the upper and lower portions of the cavity to open and close the opening, and the sliding. Microwave thawing apparatus comprising a working rod for operating the plate and a motor for rotating the operating rod while the forward and reverse rotation by the controller. The method according to claim 1 or 2, The center portion of the waveguide structure has a stub tuner that prevents microwaves from being attenuated by reflected waves generated when the microwaves are irradiated to the thawing chamber, a directional coupler that senses the reflected waves, and a circulator that converts the reflected waves into heat. Is attached, and the other end of the thawing apparatus using a microwave, characterized in that connected to the microwave generating chamber by a launcher to prevent breakage of the magnetron. The method of claim 3, wherein The magnetron oscillates microwave of 915Mhz, the thawing device using a microwave, characterized in that the power consumption is more than 30Kw. The method of claim 3, wherein And a second detection sensor attached to the launcher to detect the temperature of the magnetron, and a second detection sensor to detect the arc generated from the magnetron. The method of claim 3, wherein One side of the circulator is a thawing apparatus using a microwave, characterized in that the water rod is further attached to the inside to be able to thermally convert the absorbed reflected wave. The method of claim 1, A shielding plate is installed inside the thawing chamber to prevent the irradiated microwaves from leaking to the outside of the thawing chamber, and a reflecting plate is attached to one side of the shielding plate to uniformly disperse the microwaves inside the thawing chamber. The thawing apparatus using a microwave, characterized in that the upper side is attached with an infrared temperature sensor for sensing the temperature of the frozen food.

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