JPH11329712A - High frequency heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high frequency heating device capable of reducing temperature difference between a top side and a down side of food with reduced high frequency wave loss, enabling to improve assembly workability and maintenance operability. SOLUTION: This heating device supplies high frequency waves from upper and lower openings 3 for high frequency wave irradiation by putting a ring conveyer belt 6 in a plurality of continuous heating rooms 1, for passing through heating rooms 1, wherein a magnetron 4 supplies directly a high frequency wave through a wave guide 5 to the upper part of the heating rooms 1, and the magnetrons 4 which are provided under the heating rooms 1 in a side- looking manner, in the plurality of power-supply boxes 8, supply high frequency waves to the lower part of the heating rooms 1 through short wave guides 5, and therefore enables to assemble the apparatus and perform its maintenance without difficult and reduce losses of high frequency waves. The conveyer belt 6 passes through a lower level than the power-supply boxes 8 and circularly rotates through the heating rooms 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveyor-type high-frequency heating device using high-frequency waves, and more particularly to improvement in installation, assembling and maintenance.

[0002]

BACKGROUND OF THE INVENTION Industrial use of high frequency power has been the earliest attempted in the food sector. When utilizing the high-frequency treatment in the food industry, the following items can be mentioned as advantages as compared with other treatment methods.

(1) Heating is quick, and the inside can be heated relatively. (2) Only foods inside can be selectively heated by passing through containers and packaging.

(3) Relatively uniform heating is possible. (4) The heating temperature can be easily controlled, and automation and labor saving can be expected.

(5) Since heating is clean and heat radiation and exhaust from the apparatus are small, costs for cooling and environmental measures can be reduced.

Taking advantage of these advantages, practical applications such as thawing of frozen foods, drying of livestock products, marine products, and agricultural products, and reheating and cooking in large quantities have been promoted, and further spread is expected in the future. .

Conventionally, this type of high-frequency heating apparatus is generally shown in FIG. Reference numeral 1 denotes a heating chamber. The heating chamber 1 is provided with an opening 7 for passing an object to be heated at an inlet and an outlet, and a radio wave leakage prevention mechanism 2 is provided at the opening 7. A plurality of high-frequency irradiation openings 3 are provided on the upper surface of the heating chamber 1, and high-frequency waves generated by a plurality of high-frequency power supplies 4 pass through the plurality of waveguides 5 and are irradiated into the heating chamber 1 from the plurality of openings 3. It has become.

[0008]

However, in the conventional high-frequency heating apparatus, the heating chamber 1 and the high-frequency power supply 4 are separated from each other, and the high-frequency irradiation opening 3 is provided in the heating chamber 1.
It is only on the upper surface of. Heating chamber 1 and high frequency power supply 4
When separated, the waveguide 5 for transmitting the high frequency generated by the high frequency power supply 3 to the heating chamber 1 becomes longer. A high-frequency current flows through the waveguide 5, and a difference in electrical resistance occurs due to a difference in a metal material used for the waveguide 5 and a difference in a surface treatment material, and a high-frequency transmission loss due to heat generation of the waveguide 5 is reduced. Occurs. As in the case of the conventional high-frequency heating device, the longer the length of the waveguide 5, the higher the electrical resistance increases, the amount of heat generated in the waveguide 5 increases, the transmission efficiency decreases, and the food heating efficiency decreases. It will be.

In addition, an installation space for the high-frequency power supply 4 is required separately from the main body of the heating chamber 1, so that the installation area of the entire high-frequency heating device becomes very large. Therefore,
Depending on the area and shape of the installation location, it may be impossible to perform the predetermined installation. In that case, it is necessary to change the waveguide 5 connecting the high-frequency power supply 4 and the heating chamber 1 in accordance with the installation state, and it is necessary to adjust the output in the installed state, and the installation work becomes troublesome.

[0010] Further, since the high frequency irradiation opening 3 is located only on the upper surface of the heating chamber 1, the temperature difference between the upper and lower portions of the food becomes larger than that of the thick food. In general, it is said that high-frequency heating has a property of penetrating into food, so that uniform heating is possible. However, since it is not considered that there is a property of selectively heating only the permeated interior, if a high frequency of the same intensity is applied, the vicinity of the surface and the interior should be similarly heated.
In practice, when a high frequency is applied to a food, the high frequency advances from the surface to the inside, and attenuates by the amount heated during the process, so that the absorbed high frequency attenuates exponentially rapidly as it goes inside. Therefore, a thick food has a temperature difference between the upper and lower surfaces, causing uneven heating. As a countermeasure for this, as a method of arranging the high-frequency irradiation opening 3 below the heating chamber 1, a method of coupling the high-frequency power supply 4 with the waveguide 5 as in the related art and a method of arranging the high-frequency power supply 4 directly on the lower surface are considered. Can be

However, the former involves an increase in heat loss in the waveguide 5, the latter involves an operation in which a person enters the lower part of the high-frequency heating device during assembly, and a service in which a person enters below the high-frequency heating device during service. Very poor workability such as removing the belt.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a plurality of connected heating chambers for heating an object to be heated, an opening for passing an object to be heated at an inlet and an outlet of the heating chamber,
The high-frequency leakage prevention mechanism provided at the entrance and the exit of the heating chamber, the high-frequency leakage prevention mechanism of the heating chamber, and the entrance, the exit, and the heating chamber are passed through the lower outside of the heating chamber to form a ring. The conveyor belt that moves in connection with the upper and lower surfaces of the heating chamber, an opening that guides high-frequency waves into the heating chamber, a waveguide high-frequency power supply, the heating chamber, and the conveyor belt are held and the conveyor belt is driven. A power supply box for accommodating a high-frequency power supply and a frame for fixing the driving means, wherein the power supply box is laterally attached to a space between the lower surface of the heating chamber and the conveyor belt passing outside and below the heating chamber. It is what it was.

According to the above-mentioned invention, since the high-frequency power supply can be provided near the opening provided on the lower surface of the heating chamber, the waveguide connecting the opening and the high-frequency power supply can be shortened. Therefore, high-frequency power loss in the waveguide can be minimized.

Further, since the high-frequency power supply is installed from the side of the heating chamber, maintenance when the high-frequency power supply fails can be easily performed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is provided with a plurality of continuous heating chambers for heating an object to be heated, openings for passing the object to be heated at inlets and outlets of the heating chamber, and inlets and outlets of the heating chamber. A high-frequency leakage prevention mechanism, a high-frequency leakage prevention mechanism for the heating chamber, a conveyor belt that passes through an inlet, an outlet, and a heating chamber, passes below and below the outside of the heating chamber, and is connected in an annular manner to move; On the upper and lower surfaces of the chamber, an opening for guiding high-frequency waves into the heating chamber, a waveguide, a high-frequency power supply, the heating chamber, a frame for holding the conveyor belt, and fixing driving means for driving the conveyor belt, A power supply box for storing a power supply is provided, and the power supply box is attached from the side to a space between the lower surface of the heating chamber and the conveyor belt passing below the outside of the heating chamber.

Since the high-frequency power supply can be provided near the opening provided on the lower surface of the heating chamber, the waveguide connecting the opening and the high-frequency power supply can be made as short as possible.

Therefore, high-frequency power loss in the waveguide can be minimized. In addition, since the high-frequency power supply is installed from the side of the heating chamber, maintenance can be easily performed when the high-frequency power supply fails.

Further, a plurality of power supply boxes are provided, each of which is independent. According to this configuration, assembling and maintenance of the high-frequency power supply can be performed at a position or place that is easy for the operator to perform, so that assemblability and maintainability can be improved.

The power supply box is housed in an opening provided in the frame. The dead space on the lower surface of the heating chamber can be effectively utilized, and the outer shape of the high-frequency heating device can be reduced, so that the installation efficiency can be improved.

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a cross-sectional view showing a high-frequency heating apparatus according to a first embodiment of the present invention, FIG. 2 is a side sectional view showing a main part of the high-frequency heating apparatus, and FIG. FIG.

1 to 3, a rotating stirrer 10 for uniformly distributing high frequency is provided on the upper and lower surfaces of a plurality of substantially rectangular parallelepiped heating chambers 1, and a stirrer motor 11 provided outside the upper and lower surfaces of the heating chamber 1 is provided. Rotate with. A high-frequency power supply 4 is provided on the upper and lower surfaces of the heating chamber 1, and is connected to the heating chamber 1 by a waveguide 5. Five heating chambers 1 of this configuration are arranged in a straight line with the left and right walls shared with each other, and a radio wave leakage prevention mechanism 2 is provided at the opening of the two outermost faces. The wave leakage prevention mechanism 2 and the five heating chambers 1 are provided through the opening 7 in the mutually shared left and right walls, and the radio wave leakage prevention mechanism 2 and the heating chamber 1 are provided.
The heating chamber 1 is passed through a conveyor belt 6 woven of aramid fiber and the surface of which is coated with fluorine, passes through the lower surface of the heating chamber 1 and is connected in an annular manner. The conveyor belt 6 is rotated by a tension applied by a driving roller 12 and three rotating rollers 13 provided outside the heating chamber 1. The traveling direction of the belt 6 is as shown by the arrow in FIG. On the upper surfaces of the five heating chambers 1, two high-frequency power sources 4 (a total of ten), a waveguide 5 and an opening 3 are provided. This high-frequency power supply 4 is a small, low-output (8
00W). On the lower surface of the heating chamber 1, two (10 in total) high-frequency power supplies 4 and waveguides 5 are provided.
And an opening 3 are provided. The 20 openings 3 on the upper and lower surfaces of the heating chamber 1 are arranged so that the upper and lower openings 3 do not overlap in the width direction of the conveyor belt 6 which is orthogonal to the traveling direction of the conveyor belt 6. Two under the heating chamber 1 (total 1
0) high-frequency power supplies 4
Are inserted into and fixed to the opening of the conveyor frame 9 provided between the lower surface of the heating chamber 1 and the conveyor belt 6 passing through the lower surface of the heating chamber 1 from two side directions except for the opening 7 through which the conveyor belt 6 passes. In the individual power supply box 8 on the lower surface of the heating chamber 1, in addition to the high-frequency power supply 4 such as a magnetron, a high-voltage capacitor, a high-voltage transformer, and a high-voltage diode, electric parts (not shown) such as a cooling fan, a fuse, and a relay are also mounted. I have. Adjacent wall surfaces of the individual power supply boxes 8 are connected by a hollow pipe (not shown), and each power supply box 8 is electrically connected by a connector in the hollow pipe by a lead wire (not shown). The front opening of the power supply box 8 is covered with a cover 15. All the high-frequency power supplies 4 on the upper surface of the heating chamber 1 are installed in a power supply box composed of the upper surface of the heating chamber 1, a decorative frame 16 and a decorative top plate 17, and the entire side surface of the heating chamber 1 is covered with a decorative plate 18. . Reference numeral 19 denotes an operation panel for controlling a conveyor speed and a high-frequency output and performing operations for starting and ending cooking.

Next, the operation and operation will be described. Since each heating chamber 1 is provided with two high-frequency irradiation openings 3 on the upper surface and two on the lower surface, high-frequency power can be applied to both relatively thick food from the upper and lower surfaces of the food. Can be. The high frequency waves from the upper surface of the food proceed to the lower surface while heating and attenuating the surface. When it reaches the lower surface, it attenuates exponentially. On the other hand, the high frequency from the lower surface of the food material also proceeds while attenuating from the upper surface to the upper surface. Therefore, when high frequency is supplied to the food from the upper and lower surfaces, the temperature difference between the upper and lower surfaces of the food is greatly reduced.

By providing the required number of high-frequency power supplies 4 between the lower surface of the heating chamber 1 and the conveyor belt 6 passing through the lower surface of the heating chamber 1, the high-frequency irradiation opening 3 and the high-frequency power supply 4 on the lower surface of the heating chamber 1 are connected. Since they can be close to each other, the waveguide 5 connecting them can be shortened. Therefore, high-frequency loss in the waveguide 5 can be suppressed.

Further, since the plurality of high-frequency power supplies 4 on the lower surface of the heating chamber 1 are each mounted on a single power supply box 8, a high-frequency power supply 4 such as a magnetron, a high-voltage condenser, a high-voltage transformer, a high-voltage diode, a cooling fan, Installation work of electric parts such as fuses and relays can also be performed at a place and a position where the worker can easily work.
Since the high-frequency power supply 4 in the power supply box 8 is also divided into small and low-power outputs when attached to the conveyor frame 9, the power supply box 8 itself can be reduced in weight and can be performed alone. Since the power supply box 8 is attached to the opening of the conveyor frame 9 from the side of the heating chamber 1, the power supply box 8
Maintenance when electric components of the high-frequency power supply 4 and the cooling fan in the unit fail can be easily performed only by removing the cover 15 of the power supply box 8.

Further, the power supply box 8 can be made lower than the outer shape of the decorative plate 18 covering the heating chamber, and the installation space can be minimized.

[0027]

As described above, the high-frequency heating apparatus according to the present invention reduces the temperature difference between the upper and lower surfaces of the food material, reduces the high-frequency loss in the waveguide, and improves the workability of assembly and maintenance. Can be achieved. In addition, by integrating the heating chamber of the high-frequency heating device and the high-frequency power supply, installation efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a high-frequency heating device according to an embodiment of the present invention.

FIG. 2 is a side sectional view of a main part showing the high-frequency heating device.

FIG. 3 is a top view of the high-frequency heating device.

FIG. 4 is a diagram showing a system of a conventional high-frequency heating device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating room 3 High frequency irradiation opening 4 High frequency power supply 5 Waveguide 6 Conveyor belt 7 Food material opening 8 Power supply box 9 Conveyor frame

Claims (3)

[Claims] 1. A plurality of connected heating chambers for heating an object to be heated, an opening for passing the object to be heated at an inlet and an outlet of the heating chamber,
A high-frequency leakage prevention mechanism provided at the entrance and exit of the heating chamber, a high-frequency leakage prevention mechanism of the heating chamber, A conveyor belt connected and moving to the heating chamber; an upper surface and a lower surface of the heating chamber, an opening for guiding high-frequency waves into the heating chamber, a waveguide, a high-frequency power supply, the heating chamber, and the conveyor belt; A frame for fixing a driving means for driving the belt; and a power supply box for storing a high-frequency power supply, wherein the power supply box is provided in a space between the lower surface of the heating chamber and the conveyor belt passing below the outside of the heating chamber. High-frequency heating device installed from the side. 2. The high-frequency heating apparatus according to claim 1, wherein a plurality of power supply boxes are provided, each of which is independent. 3. The high-frequency heating device according to claim 1, wherein the power supply box is housed in an opening provided in the frame.