JP2006086004A - Defrosted state determining method and defrosting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To determine a defrosted state of an object to be defrosted in its surface and center part. <P>SOLUTION: An electric wave is irradiated to the object 1 to be defrosted by changing its frequency by an electric wave generating means 3, the amount of reflection of the electric wave is detected by an electric wave reflection amount detecting means 4, and the defrosted state of the object 1 to be defrosted in its surface and center part is determined by the detected value of the electric wave reflection amount detecting means 4. In addition, this defrosting device is equipped with a defrosting chamber 2 to hold the object 1 to be defrosted, the electric wave generating means 3 which irradiates the electric wave to the object 1 to be defrosted and can change the frequency of the electric wave, the electric wave reflection amount detecting means 4 to detect the amount of reflection of the electric wave irradiated to the object 1 to be defrosted, and a control means 9 to determine the defrosted state of the object 1 to be defrosted in its surface and center part from the detected value of the electric wave reflection amount detecting means 4 by changing the frequency by controlling the electric wave generating means 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a thawing state determination method for determining a thawing state of frozen food and a thawing device for thawing frozen food.

  2. Description of the Related Art Conventionally, a technique is known in which the amount of reflected microwaves applied to food is detected and the food state of frozen food or non-frozen food is determined based on the detected value (Patent Document 1).

Japanese Patent Publication No. 7-26736

  The technique described in Patent Document 1 can determine the thawing of the surface of the food, but cannot determine the center of the food.

  An object of the present invention is to determine the thawing state of the surface and the center of the object to be thawed.

  The present invention has been made to solve the above-described problems, and the invention according to claim 1 is directed to irradiating the object to be thawed with radio waves by changing the frequency from the radio wave generating means, and using the radio wave reflection amount detecting means. The radio wave reflection amount is detected, and the thawing state of the surface and center of the object to be thawed is determined from the detection value of the radio wave reflection amount detection means.

  The invention described in claim 2 is a thawing chamber for storing a material to be thawed, a radio wave generating means for radiating a radio wave to the material to be thawed, a variable frequency of the radio wave, and a reflection amount of the radio wave irradiated to the material to be thawed. A radio wave reflection amount detecting means for detecting, and a control means for controlling the radio wave generating means to change the frequency and for determining the thawing state of the surface and the center of the object to be thawed from the detection value of the radio wave reflection amount detecting means. It is characterized by providing.

  According to this invention, it is possible to determine the thawing state of the surface and the center of the object to be thawed.

  Next, an embodiment of the present invention will be described. In this embodiment, the thawing state determination method of the present invention, that is, a food wave (hereinafter referred to as “the object to be thawed”) is irradiated with radio waves by changing the frequency from the radio wave generating means, and the radio wave reflection amount detecting means. Is a thawing device for detecting a reflection amount of the radio wave and performing a thawing state determination method for determining the thawing state of the surface and the center of the object to be thawed from the detection value of the radio wave reflection amount detection means. First, this decompression device will be described.

  The thawing device includes a thawing chamber for storing a material to be thawed, a radio wave generating means for radiating a radio wave to the material to be thawed, a variable frequency of the radio wave, and a radio wave reflection for detecting a reflection amount of the radio wave irradiated to the material to be thawed A quantity detecting means, and a control means for controlling the radio wave generating means to change the frequency and determining the thawing state of the surface and the center of the object to be thawed from the detection value of the radio wave reflection quantity detecting means.

The operation of the thawing device having such a configuration will be described. First, the object to be thawed accommodated in the thawing chamber is irradiated with radio waves from the radio wave generating means while changing the frequency. This radio wave is absorbed by the object to be thawed and becomes a partially reflected wave. The radio wave reflection amount detecting means detects the reflection amount of the reflected wave. The control means determines the thawing state of the object to be thawed from this reflection amount. Thereby, the thawing state of the thawed part and the frozen part of the material to be thawed is determined.

  Next, components of this embodiment will be described. First, the thawing chamber is an area used for thawing the material to be thawed, and means a room, room, container, or tank in which the material to be thawed can be stored and taken in and can also be called a thawing region or a thawing space.

  The radio wave generating means has a function of irradiating the object to be thawed with radio waves while changing the frequency. The frequency range in which the generated radio wave changes is preferably 1 MHz to 3 GHz.

  The radio wave reflection amount detecting means detects a reflection amount of the radio wave irradiated to the object to be thawed from the radio wave generating means. An antenna can be used as the radio wave reflection amount detecting means.

  The control means has a function of controlling the radio wave generation means and determining the thawing state of the object to be thawed from the reflection amount detected by the radio wave reflection amount detection means. This control means can also be called determination means. Further, the control means is not limited to the determination from the reflection amount, and the reflectance (reflection amount) obtained by calculation based on the irradiation amount from the radio wave generation means and the reflection amount detected by the radio wave reflection amount detection means. It is also possible to determine the thawing state of the object to be thawed from the value obtained by dividing the value by the irradiation amount. This control means can be configured to determine the thawing state of the surface of the object to be thawed and to determine the thawing state of the central part. These determinations are such that the higher the frequency of the radio wave, the easier it is to be absorbed on the surface of the object to be thawed, and the lower the frequency of the radio wave, the more centered from the surface of the object to be thawed. It is carried out by utilizing the property that it is absorbed over the part and not only on the surface of the object to be thawed.

  The control means determines the thawing state of the surface of the object to be thawed when radiating a high frequency radio wave from the radio wave generating means, and determines the thawing state of the center of the object to be thawed when radiating a low frequency radio wave. judge.

  In order to determine each thawing state, it is necessary to determine a reference value for thawing determination of an object to be thawed. First, the control means irradiates the object to be thawed with high and low frequencies by changing the frequency of the radio wave generating means. The radio wave reflection amount detecting means detects the reflection amount from the object to be thawed with a change in the frequency of the radio wave. Then, the control means determines a reference value for determining that the surface of the object to be thawed has been thawed based on the reflection amount or the reflectance detected by the radio wave reflection amount detection means when high frequency and low frequency are irradiated. A reference value for determining that the center of the thawed material has been thawed is determined according to a preset calculation formula or setting table.

  The radio wave generation means irradiates the object to be thawed with radio waves while changing the frequency. The radio wave reflection amount detection means detects the reflection amount when high frequency and low frequency are irradiated from the radio wave generation means. The control means determines that the surface and center of the object to be thawed have been thawed by comparing with a set reference value based on the reflection amount or the reflectance detected by the radio wave reflection amount detection means. . Further, the present invention is not limited to this, and by determining the reflection amount or reflectance value measured before the start of thawing, the thickness of the object to be thawed and the degree of freezing can be determined.

More specifically, the determination of the thawing state of the surface of the object to be thawed will be described. The said control means determines the thawing | decompression state of the surface of a to-be-thawed object, when the said electromagnetic wave generation means irradiates a high frequency radio wave. The control means determines that the surface of the object to be thawed is thawed if the reflection amount or the reflectance detected by the radio wave reflection amount detection means is lower than a reference value, and if it is higher than the reference value, the surface of the object to be thawed Is determined not to be thawed.

  Next, the determination of the thawing state at the center of the object to be thawed will be described. The control means determines the thawing state of the center of the object to be thawed by the radio wave generating means irradiating a low frequency radio wave. The control means determines that the center of the object to be thawed is thawed if the reflection amount or the reflectance detected by the radio wave reflection amount detection means is lower than a reference value, and if it is higher than the reference value, It is determined that the center is not thawed.

  And, when the control means detects that the amount of reflection detected by the radio wave reflection amount detection means or the reflectance is lower than a reference value in both cases of high frequency and low frequency irradiation by the radio wave generation means, It is determined that both the surface and the center of the object to be thawed are thawed, and control is performed to end the thaw process. In this case, the control means sets the time for performing the thawing process, but if the material to be thawed is thawed within the set time, the control means can control to end the thawing process. Moreover, the said control means can control to perform a thawing | decompression process continuously, if the to-be-thawed object is not defrosting after progress for a set time.

  As described above, according to this embodiment, the control means changes the frequency of the radio wave from the radio wave generation means to high or low to detect the reflection amount or the reflectivity of the surface and center of the object to be thawed. Thus, the thawing state can be accurately determined regardless of the size of the object to be thawed.

  Hereinafter, specific examples of the decompression apparatus embodying the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view of a longitudinal section showing a schematic configuration of a thawing device according to an embodiment of the present invention. FIG. 2 is a flowchart showing a determination procedure according to the embodiment of the present invention.

  The thawing device according to the embodiment includes a thawing chamber 2 for storing the material 1 to be thawed, a radio wave generator 3 for radiating radio waves to the material 1 to be thawed in the thawing chamber 2, and The receiving antenna 4 that detects the amount of reflection of the irradiated radio wave, the steam supply means 5 that supplies steam into the thawing chamber 2, the decompression means 6 that sucks and exhausts the interior of the thawing chamber 2 and maintains the pressure at a low pressure, and Further, a decompression means 7 for restoring pressure by introducing outside air into the thawing chamber 2, a pressure detector 8 for detecting the pressure in the thawing chamber 2, and signals from the receiving antenna 4 and the pressure detector 8 are input. Based on the control procedure stored in the memory, a controller 9 that performs thawing control and thawing state determination control of the object 1 to be thawed is provided as a main part.

  The thawing chamber 2 is provided with a door (not shown) for taking in and out the article 1 to be thawed.

  The radio wave generator 3 irradiates the object 1 to be thawed with radio waves, and has a function of changing the frequency of the radio waves. In this embodiment, the variable frequency range is 1 MHz to 3 GHz.

  The receiving antenna 4 detects the amount of reflected waves from the object 1 to be thawed, and is installed on the upper surface of the thawing chamber 2.

  The steam supply means 5 is connected to the thawing chamber 2 at one end, supplies clean steam into the thawing chamber 2, and defrosts the material 1 to be thawed. The steam supply means 5 has a configuration in which a water softener, a reboiler, and a steam supply valve (all not shown) are provided in this order from the thawing chamber 2 side. The decompression means 6 has a configuration in which a steam ejector, a heat exchanger, a check valve, and a water seal vacuum pump (all not shown) are provided in this order from the thawing chamber 2 side. The return pressure means 7 has a configuration in which a return pressure valve and a sterilization filter (both not shown) are provided from the thawing chamber 2 side.

  The thawing chamber 2 includes a display 10 for displaying various settings such as a thawing mode, an operating state, and a thawing state of an object to be thawed on a front door (not shown). In the thawing chamber 2, shelves 11, 11,... Each shelf 11 shown in FIG. 1 is made of a material through which radio waves can pass.

  The controller 9 has a decompression processing function and a decompression state determination function. The controller 9 receives signals from the receiving antenna 4 and the pressure detector 8, and follows the predetermined thawing process procedure (program) to generate the radio wave generator 3, the steam supply means 5, the pressure reducing means 6, and the like. The return pressure means 7 and the display 10 are controlled.

  The controller 9 performs the surface thawing state determination and the center thawing state determination of the object 1 to be thawed in the thawing process procedure. In the decompression state determination, a signal can be output from the controller 9 to the display device 10 so that the user can confirm the decompression state on the display device 10. Hereinafter, determination of the thawing state of the object 1 to be thawed according to this embodiment will be described with reference to FIGS.

  First, the object 1 to be thawed is placed on each shelf 11, the thawing chamber 2 is sealed, and a reference value for thawing determination of the object 1 to be thawed is determined. The controller 9 changes the frequency of the radio wave generator 3 between 1 MHz and 3 GHz to irradiate the object 1 to be thawed with high and low frequencies. The receiving antenna 4 detects the amount of reflection from the object 1 to be thawed as the frequency of the radio wave changes. And the said controller 9 is based on the detection value of the said receiving antenna 4 when irradiating a high frequency, The reference value X which determines that the surface of the to-be-thawed object 1 thaw | defrosted, and the said when a low frequency is irradiated Based on the detection value of the receiving antenna 4, a reference value Y for determining that the central portion of the object 1 to be thawed has been thawed is automatically calculated according to a preset formula or setting table (step S1). After the determination of the reference values X and Y, the controller 9 temporarily stops the irradiation of radio waves from the radio wave generator 3.

  Then, the controller 9 operates the decompression means 6 with the decompression means 7 closed, exhausts only the decompression, and then supplies steam from the steam supply means 5 while reducing the pressure. By exhausting the air, the air in the thawing chamber 2 is removed. Subsequently, the controller 9 continuously operates the steam supply means 5, that is, performs the thawing process of the object 1 while adjusting the supply of steam according to the detected pressure of the pressure detector 8. This thawing process is performed for a time set by the display 10.

  In step S2, the controller 9 causes the radio wave generator 3 to irradiate the object 1 to be thawed at a predetermined timing during the thawing process. The controller 9 inputs the amount of reflection detected by the receiving antenna 4. In step S3, the controller 9 determines whether or not the detection value of the receiving antenna 4 is equal to or greater than a reference value X within the time T1. If the reference value X is greater than or equal to the reference value X, the display 10 indicates that the surface of the object 1 to be thawed is frozen (step S4). Is displayed on the display 10 (step S5). Then, the process proceeds to step S6.

  The radio wave generator 3 irradiates the high frequency K1 Hz for the T1 time, and then irradiates the low frequency K2 Hz for the T2 time at the set timing (step S6). In step S7, the controller 9 determines whether or not the detection value of the receiving antenna 4 is equal to or greater than a reference value Y within the time T2. If it is equal to or greater than the reference value Y, the display 10 displays that the center of the object 1 to be thawed is frozen (step S8), and performs a process of continuing the thawing process (step S9). After the process of step S9, the thawed object 1 has not been completely thawed so that the process proceeds to step S2.

  When the detected value of the receiving antenna 4 is equal to or less than the reference value Y within the time T2, the controller 9 displays on the display 10 that the center of the object 1 is being thawed (step) S10). In step S11, if the determination in step S3 is YES, the controller 9 determines that the object 1 to be thawed has been completely thawed, and ends the thawing process (step S12). If the controller 9 determines to end the decompression process, the controller 9 terminates the decompression process without lapse of the set time. Further, if the controller 9 does not determine that the decompression process has ended even after the set time has elapsed, the controller 9 can extend the set time and continue the decompression process.

  When the thawing process is completed, the controller 9 stops the operation of the steam supply means 5 and the decompression means 6 and operates the return pressure means 7 to return the inside of the thawing chamber 2 to atmospheric pressure.

  According to the embodiment described above, the controller 9 can determine the thawing state of the surface and the center of the object 1 by irradiating with the frequency of the radio wave changed. In addition, this allows the object 1 to be thawed to be taken out from the thawing chamber 2 while being thawed to the center without being thawed excessively.

It is explanatory drawing of the longitudinal cross-section which shows schematic structure of the thawing | decompression apparatus of the Example of this invention. It is a flowchart which shows the determination procedure of the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thawed object 2 Thawing room 3 Radio wave generator 4 Receiving antenna 9 Controller

Claims (2)

  The object to be thawed 1 is irradiated with radio waves by changing the frequency from the radio wave generating means 3, the amount of reflection of the radio waves is detected by the radio wave reflection amount detecting means 4, and the object to be thawed is detected from the detection value of the radio wave reflection amount detecting means 4. A method for determining a thawing state, comprising determining a thawing state of a surface and a central portion of 1. A thawing chamber 2 that houses the material 1 to be thawed, a radio wave generating means 3 that radiates radio waves to the material 1 to be thawed, and a radio wave reflection that detects the amount of reflection of the radio waves irradiated to the material 1 A quantity detecting means 4 and a control means 9 for controlling the radio wave generating means 3 to change the frequency and judging the thawing state of the surface and the center of the object 1 from the detection value of the radio wave reflection quantity detecting means 4; A thawing device comprising:

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