JPS5940435B2 - High frequency thawing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high frequency thawing device for frozen products, etc., and is aimed at improving insulation properties and reliability thereof.

In conventional defrosting using dielectric heating, the defrosting operation is generally performed using a high frequency of several Mll2 or higher.

FIG. 1 shows a thawing device that performs dielectric heating and thawing at a relatively low frequency, such as 13 MH2, with two electrodes, upper and lower, sandwiching the object to be thawed. In Fig. 1, indicates the thawing chamber, the bottom surface of which is a mounting plate 2 made of an insulator, and the side, rear, and top surfaces of the thawing chamber wall 3 made of a material such as aluminum with good conductivity. ing. 4
is the material to be thawed.

It is housed in a hygroscopic cardboard box 4', and an upper electrode 5 connected to the ground side is movably attached to the upper part by an electrode lifting device 6. □ is an electrode box provided below the mounting plate 2 of the thawing chamber 1, and this electrode box T and the wall surface 3 of the thawing chamber are electrically connected. A lower electrode 8 is provided inside the electrode box T with a predetermined gap between the mounting plate 2 and the electrode box □, and is connected to the high voltage side.

Reference numeral 9 denotes a high-frequency oscillator unit that supplies high-frequency energy to the object 4 to be thawed, and is shielded to prevent noise from leaking to the outside.

Reference numerals 10 and 11 are power supply lines that feed power to the lower electrode 8 and the upper electrode 5, respectively.

In terms of the circuit, the thawing chamber wall 3, the electrode box 1, and the chassis of the high frequency oscillator section 9 are grounded together with the upper electrode 5. In this configuration, if a highly water-absorbent material such as a cardboard box 4' is used as the box for storing the object 4 to be thawed, the cardboard box 4' is in contact with the wall surface 3 of the thawing chamber 1 in the thawing chamber 1. The problem occurs when it is put into the

FIG. 1 shows a state in which the handles of the cardboard box 4' are in contact with each other. During thawing, the cardboard box 4' absorbs moisture from the thawed object 4 (meat juice), or in the case of the thawed object packed in ice, the thawed moisture is absorbed by the cardboard box 4' or flows onto the mounting plate 2. Originally, a high frequency current should flow through the upper electrode 5 and the lower electrode 10. However, due to the above phenomenon, since the wall surface 3 of the defrosting chamber is connected to the ground side, the cardboard box 4
' is the ground side, and the distance from the lower electrode 10, which is the high voltage side, is very short. Since the dielectric constant of water and trip is very large, the high frequency electric field force ζ is concentrated in damp areas. Therefore, the high frequency current flows through the cardboard box 4'. At this time, since the trip and moisture contain salt, etc., the mounting plate 2 and the cardboard box 4' are likely to track, causing carbonization, smoke, and ignition, which can cause the equipment to burn, which is extremely dangerous. It is. As described above, conventional defrosting devices have poor insulation and lack safety depending on how they are used. The present invention provides a high-frequency decompressing device that eliminates the conventional drawbacks, and one embodiment of the present invention will be described below with reference to the drawings.

In Figs. 2, 3, and 4, 1 is a thawing chamber, which is composed of a mounting plate 2, a thawing chamber wall 3 made of grounded and conductive material, and inside the thawing chamber 1. An object 4 to be thawed is stored in a cardboard box 4'. Reference numeral 5 denotes an upper electrode connected to the ground side, which is covered with a cover 5' made of an insulator so that the object 4 to be thawed does not come into direct contact with the upper electrode 5.

The upper electrode 5 is fixed to an electrode lifting device 6 so that its height can be adjusted according to the thickness of the object 4 to be thawed. Reference numeral 7 designates an electrode box, which is electrically connected to the wall surface 3 of the thawing chamber over the entire circumferential wall. It has a lower electrode 8 provided with a gap.

This lower electrode 8 is connected to the high voltage side. 9 is a high frequency oscillator W) that supplies high frequency energy. 12 is the power supply 9
．． Reference numerals 10, 11, and 13 are power supply lines that respectively supply power to the lower electrode 8, the upper electrode 5, and the high-frequency oscillator section 9.

Reference numeral 14 denotes an L-shaped plate-like first insulator, and one side of the first insulator is fixed to the bottom of the thawing chamber wall 3 and the top of the electrode box 7 together with the mounting plate 2 in a sandwich-like manner.

A sealant 15 such as silicone is interposed between the mounting plate 2 and the first insulator 14. The other side stands upward along the wall surface 3 of the defrosting chamber. A second insulator 14' is fixed to the wall surface 3 of the defrosting chamber so that this raised end forms a sandwich with the wall surface 3 of the defrosting chamber. The second insulator 14' projects toward the interior of the defrosting chamber. 15' is the first
A sealant such as silicone is applied to cover the upright tip of the first insulator 14 to prevent moisture from entering the gap between the first insulator 14 and the thawed nitrogen wall surface 3.

In order to maintain the thawing chamber 1 in a cool atmosphere, it is equipped with a cooling coil 16, a cooling fan 17, a condensing coil 18, a compressor 19, etc., and communicates with the thawing chamber 1 through an intake port 20 and an exhaust port 21. There is. 22 is the main body of the defrosting device, and 23 is an input door.

FIG. 5 is a schematic circuit diagram of the main part of the present invention.

As shown in the figure, the thawing chamber wall surface 3, the upper electrode 5, and the chassis of the high frequency oscillator section 9 are grounded. FIG. 6 shows an example in which the insulation properties are further improved.
The upper surface of the second insulator 14' is sloped so that the end thereof forms an angle α toward the bottom, and moisture (for cleaning the thawing chamber or cooling the thawing chamber 1) is placed on the upper surface of the second insulator 14'. (generated by condensed water on the wall surface 3 of the defrosting chamber) does not accumulate. The decompression operation of the present invention will be explained next. The object to be thawed 4 stored in a cardboard box 4' is stored in the thawing chamber 1, and the upper electrode 5 is adjusted so as to be in contact with the cardboard box 4' or to provide an appropriate gap. When it is operated, the object to be thawed 4 is heated due to dielectric loss and thawing begins. As thawing progresses, the ice will melt and become water in the case of tripping from the thawing object 4 or ice-packed thawing object, such as shrimp block. Even if the cardboard box 4' absorbs moisture or flows over the mounting plate 2, it will not come into contact with the thawing chamber wall surface 3 and the upper electrode 5, which are connected to the ground side, and there will be no short-circuit phenomenon of high-frequency current and tracking. There is no need to worry about charcoal smoke or ignition. This is because even if the cardboard box 4' is casually thrown into the thawing chamber 1, the second insulator 14' protrudes so that it does not come into contact with the wall surface 3 of the thawing chamber whose position is restricted, and the upper electrode 5 This is because it is covered with the cover 5'. Trips and moisture flowing on the mounting plate 2 do not come into contact with the thawing chamber wall surface 3 due to the first insulator 14, and the insulation distance is also reduced to the second insulator 14' in the worst case.
There is no short-circuit phenomenon because it can be secured with a protrusion distance of . Furthermore, in order to improve insulation reliability, the upright end of the first insulator 14 is held down by a strong second insulator 14', and at the same time, a sealant 15' such as silicone is applied to the tip. Since it is coated, moisture does not enter between the upright portion and the wall surface 3 of the thawing chamber, and there is almost no water pooling on the second insulator 14/upper surface, thereby providing insulation. Furthermore, taking into consideration the case where the thawing device is installed at an angle, by providing an inclined portion on the upper surface of the second insulator 14' as shown in FIG. 6, it is possible to completely eliminate the accumulation of moisture. As described above, the present invention prevents moisture, trips, and contact of the cardboard box with the ground side, ensures sufficient insulation distance, and has high reliability. It is possible to provide a safe thawing device that does not cause fires due to ignition.

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view of the main parts of a conventional high-frequency thawing device;
The figure is a sectional view of a high-frequency thawing device according to an embodiment of the present invention, FIG. 3 is an enlarged sectional view of section A in FIG. 2, FIG. 4 is a plan view of the main part of the device, and FIG. A schematic circuit diagram of main parts, FIG. 6 is a sectional view of another embodiment corresponding to FIG. 3. 1... Thawing chamber, 2... Placement plate, 3...
... Defrosting chamber wall, 4... Items to be thawed, 5...
...Top electrode, 8...Bottom electrode, 14...
...First insulator, 14'...Second insulator.

Claims (1)

[Scope of Claims] 1 A defrosting chamber, a high-frequency oscillator, and a pair of electrodes are provided, the lower electrode provided at the bottom of the defrosting chamber is connected to the high voltage side, and the upper electrode provided inside the defrosting chamber is connected to the ground side, A first insulator is interposed between the mounting plate constituting the bottom surface of the thawing chamber and the bottom surface of the wall surface of the thawing chamber connected to the ground side, and a second insulator is provided that protrudes toward the thawing chamber from the wall surface of the thawing chamber. A high frequency thawing device was installed. 2. The first insulator is L-shaped, one side of which stands up for a predetermined length above the thawing chamber, and the second insulator is fixed by sandwiching the upright end with the wall surface of the thawing chamber. The high frequency thawing device according to scope 1. 3. The high frequency thawing device according to claim 2, wherein a sealing agent is applied to cover the upright tip of the first insulator. 4. The high-frequency thawing device according to claim 2, wherein the upper surface of the second insulator has an end sloped inwardly and downwardly.