JPS6012021B2 - Defrosting time control method for high frequency defrosting machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high frequency thawing machine for frozen foods such as meat and fish, and is particularly characterized by a thawing time control method.

Conventionally, thawing of frozen objects using high-frequency dielectric heating has been known, but there is no particularly powerful detection means for detecting the completion of thawing, and the general method is to set the thawing time using a timer means. It is necessary to change the timer setting depending on the size, shape, type, etc.

In particular, there was a heavy reliance on experience, which led to mistakes such as thawing too much or not thawing it enough. The present invention solves the above-mentioned drawbacks, automatically sets the defrosting end time, and stops dielectric heating.One embodiment of the present invention will be described below with reference to the drawings.

In the figure, reference numeral 1 denotes a thawing chamber, in which a pair of plate-shaped electrodes 2a and 2b are provided, and a high frequency electric field is applied between the electrodes 2a and 2b from a high frequency power source 3.

An object 4 to be thawed is placed between the electrodes 2a and 2b with an insulating plate 5 interposed therebetween. Figure 2 shows the change in high-frequency output over time when a nearly constant high-frequency electric field is applied between the opposing electrodes 2a and 2b. The application of the high-frequency electric field is stopped at the point when the defrosting is completed. The figure shows an example of objects A, B, and C to be thawed, which have different sizes and types, and their volumes have a relationship of A>B>C, and the center temperature of each object is -3 at t2, t, and time. ℃ and thawing is complete. In addition, the initial value q of the high-frequency output increases as the volume increases, and q
3, q2, q, and q3>q2>q, indicating the same problem as the decompression end time t3>et>t. From this, by knowing the initial value of the high frequency output, It is possible to approximately estimate the thawing time of the object to be thawed. From this, the initial value of the high frequency output is detected, and depending on the magnitude thereof, the application time of the high frequency electric field is controlled, and the end of defrosting is controlled. FIG. 3 is a block diagram showing one embodiment of the present invention, in which a rectifier circuit 30 is connected to a low frequency power source.
DC power is applied to the high frequency generation circuit 31 via the high frequency generating circuit 31.

The high frequency generation circuit 31 generates DC power at 10 to 10 MHz.
is converted into high-frequency power, a voltage is applied between the electrodes 2a and 2b, and the object 4 to be thawed is heated. The output of the high frequency generation circuit 31 is controlled by a control circuit 32. The control circuit 32 includes an input current detection circuit 320 that detects an input current for indirectly detecting the high frequency output of the high frequency generation circuit 31, and a timer circuit 321 that uses the output of the input current detection circuit 320 to determine the time. Make the settings and switch the switching circuit 3.
Operate 3. As is clear from the above-mentioned embodiments, the present invention detects the initial value of the electric signal corresponding to the high-frequency output of the high-frequency power source and sets the high-frequency application time accordingly. Because you can automatically set the defrosting end time regardless of the current situation,
There are fewer cases of defrosting or insufficient thawing,
Moreover, it can be successfully thawed without any experience, and its effects are extremely large.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a schematic configuration of an embodiment of the high-frequency thawing machine of the present invention, Fig. 2 is a characteristic diagram showing the relationship between high-frequency output and thawing time, and Fig. 3 is a control circuit of the high-frequency thawing machine of the present invention. FIG. 1... Thawing chamber, 2a, 2b... Electrode,
3...High frequency power supply, 4...Thawing object, 32
...control circuit. Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. A thawing chamber that stores an object to be thawed, a high-frequency power supply that supplies high-frequency energy to the object to be thawed, and a pair of electrodes are provided, and high-frequency electrolysis is applied between the electrodes to perform thawing by dielectric heating. The defrosting time of a high-frequency defrosting machine is characterized in that the defrosting end of the object to be defrosted is controlled by detecting the initial value of an electric signal corresponding to the high-frequency output of a high-frequency power source at the start of defrosting. Control method. 2. The thawing time is controlled such that the electric signal generated by the initial high-frequency output is detected and the thawing time is controlled such that the larger the electric signal to be thawed, the longer the thawing completion time, and the smaller the electric signal, the shorter the thawing completion time. A method for controlling the thawing time of a high-frequency thawing machine.