JP2000306661A - Tunnel type microwave continuous furnace - Google Patents

Abstract

(57) [Summary] An object of the present invention is to make the ratio of load to the same microwave output constant in a tunnel type microwave continuous furnace having excellent workability. SOLUTION: In a furnace 1 equipped with a microwave irradiation source,
By providing a conveyor belt 4 penetrating through the furnace 1 and providing lines 5 in a direction perpendicular to the running direction of the conveyor at equal intervals on this surface to serve as a reference at the time of loading, it is possible to always supply a constant load. did.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous tunnel furnace using microwaves, and more particularly to a belt conveyor used in a continuous furnace.

[0002]

2. Description of the Related Art As a heating method using microwaves, there are a tunnel type continuous furnace method and a non-tunnel type.

The non-tunnel type, that is, the type in which the door is opened and closed when a load passes and the microwave is irradiated while the door is closed and the load stays inside the furnace, has at least the shape and quantity of the passing load, etc. Since it is premised that information necessary for opening and closing the door has been input, it is easy to adjust the electric energy according to the load amount, and the load can be heated to a desired temperature. The disadvantage is that the door is closed while the radio wave is being irradiated, so that the next load cannot be applied, and the productivity is low.

On the other hand, the tunnel type continuous furnace eliminates the door, which is a cause of reducing the productivity, and provides a tunnel for preventing radio wave leakage, so that a load can be continuously supplied at any time. Since there is no opening and closing of the door, radio waves can be continuously radiated and productivity is greatly improved.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems when a continuous tunnel furnace is used in order to improve productivity. The issues of the continuous tunnel furnace are described below.

[0006] If a load is applied as needed, the amount of load accommodated in the furnace at an arbitrary time cannot be determined. The power input into the furnace is constant, and as a general characteristic of the microwave furnace, the load amount and the power amount received by the unit load are inversely proportional, so if the load amount is not determined, the power received by each load is not determined, and heating is performed. The subsequent temperature rise is unknown. In particular, when inserted by hand, various factors such as individual differences, familiarity, fatigue, etc. due to human beings are added, and the result is greatly affected.

[0007] The degree of variation will be introduced for reference. For example, frozen vegetable croquette 3 of the same size and shape per hour
When 3,000 pieces are thawed and the temperature is uniformly raised from -20 ° C to -3 ° C, an average of 10% lower temperature, -4.7 ° C, is obtained by simple calculation if an additional 3300 pieces are added. The temperature decreases, and conversely, if the number is 2,700, the average increases to -1.3 ° C.

[0008] An increase or decrease of the input amount of 10% occurs relatively easily. It is assumed that croquettes are arranged in a plane on a conveyor belt of a continuous furnace. If the running direction and the perpendicular direction of the conveyor are arranged one by one every 10 cm and 3000 pieces per hour, if the running direction is only 1 cm different and becomes 9 cm, it increases by 10%. 5mm in running direction, 5mm in right angle direction,
Even if both are different, similar results are calculated.

[0009] One of the simple solutions that comes to mind is to measure the input amount and adjust the irradiation power amount accordingly. However, even if this is realized, it will not be a solution since it will appear more complicated in actual work. For example, one part may be arranged every 9.5 cm and another part may be arranged every 10.5 cm, which are simultaneously accommodated in the furnace. In this case, no matter how the amount of irradiation power is adjusted, a temperature difference is generated between every 9.5 cm and every 10.5 cm. It is an object of the present invention to eliminate the fluctuation of the heating result due to the fluctuation of the load on the microwave tunnel continuous furnace.

[0010]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method in which objects to be heated are placed at equal intervals on the surface of a conveyor belt penetrating through a furnace, or the objects to be heated are placed on the conveyor belt. Marks are provided so that the mounted state of the object can be easily recognized.

Further, a plurality of objects to be heated can be easily placed on the mark. Therefore, the load (the object to be heated) can always be kept constant for the same microwave output, and a plurality of objects to be heated can be uniformly heated.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises a furnace equipped with a microwave irradiation source for heating an object to be heated, and a conveyor belt for mounting the object to be heated and penetrating through the furnace. In order to be able to easily recognize the placement state of the heated object, a mark is provided on the surface of the conveyor belt.

Further, the marks are made up of a number of equally spaced lines provided in a direction perpendicular to the running direction of the conveyor belt.

According to the above invention, for example, in thawing frozen vegetable croquettes, if a certain number of croquettes are placed on a line provided in a direction perpendicular to the surface of the belt, the lines are provided at equal intervals. The croquettes are also arranged at regular intervals, and the number of croquettes passing through the furnace per unit time is constant, and as a result, the croquettes are heated to a constant temperature. The work of arranging a fixed number, for example, eight pieces, at equal intervals in the perpendicular direction can be easily and stably repeated because it can be seen by the human eyes at once, but in the case of the running direction, the work is arranged in the tunnel in the order in which it is arranged. It becomes invisible, and the balance between the front and back cannot be overlooked, which increases the error. In this regard, if there is a line as a guide, the lines are arranged almost in a straight line even if they are not aligned as measured by a ruler, and they are arranged at equal intervals.

[0015]

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view (a) and a front view (b) of an embodiment of a continuous microwave tunnel furnace according to the present invention. The furnace 1 is located at the center. An inlet tunnel 2 is provided on the left side of the furnace, and an outlet tunnel 3 is provided on the right side. A conveyor belt 4 is provided through the furnace 1 and the two tunnels 2 and 3. Lines 5 are drawn at regular intervals as marks on the surface of the conveyor belt. A microwave irradiation source is provided in the furnace 1 but cannot be seen from the outside. In FIG. 1, an outer shell plate 7 in which a louver group 6 for ventilation is opened occupies a central portion. In the front view, the conveyor belt 4 is drawn in broken lines, and the furnace 1 is also drawn in broken lines.

FIG. 2 is a plan view of the vicinity of the connecting portion of the conveyor belt 4, and the direction indicated by the arrow is the running direction of the conveyor. As the material of the conveyor belt, a material excellent in heat resistance and moisture resistance is preferable. In a microwave tunnel continuous furnace, aramid fiber is generally used. In this embodiment, a case in which aramid fiber is used will be described. Both ends of the conveyor belt, which is a woven aramid fiber, adopt a piano hinge-like fitting, and have a shape that compensates for the unevenness of each other.
The ends are connected by alternately penetrating this cylinder.
The line 5 composed of perforations using aramid fiber yarns is provided at a position 10 cm from the rod 9 and is provided repeatedly at 10 cm intervals thereafter. The perforations are the same color as the conveyor belt main body, but they are raised only by the thickness of the thread, so they can be seen well from the outside, but they do not obstruct the placing of the object to be heated (load). Of course, in the case of a different color, it becomes easy to recognize and the convenience is further improved. A slightly thick string 10 made of the same aramid fiber is fixed parallel to the running direction on the upper surface of the belt and near the end in the width direction. The above-mentioned perforation 5 has two strings 10
It is provided between. The entire conveyor belt 4 is coated with a fluororesin to further improve the moisture resistance.
On both sides of the rod 9, three perforations similar to the line 5 are drawn on the right and left, respectively, which are cloth fixing threads added to the conveyor belt itself to form the above-described tube of the projection 8. . The oval shape drawn by a two-dot chain line represents the outline of the frozen vegetable croquette 11.

The operation of the above configuration will be described. Since the upper surface of the conveyor belt 4 is coated with a fluorocarbon resin having a small friction, it is easy to slip when a frozen food is placed as a load. Since the string 10 is provided, the string 10 is prevented from dropping from the belt surface. The space between the two strings 10 is a load placement area.
The line (perforation) 5 is drawn (provided) from end to end of the load placement area, and serves as a guide for the position to be placed when the load is placed. For example, when the frozen vegetable croquette 11 is heated, the tip of the croquette is aligned with the line 5, and the croquettes are arranged at regular intervals along the line, for example, in the eighth line. By arranging the croquettes uniformly and repeating this, the number of croquettes to be stored in the furnace can be kept constant at all times, and the uniformity of heating is improved.

When the croquette is thrown in by a human hand, the interval in the running direction tends to gradually change with the passage of time, but since lines at equal intervals are drawn (provided), they are always provided. The same spacing is maintained.

Further, in this embodiment, the connecting surface of the belt is line 5
, The connection portions are also arranged at equal intervals of the load.

The line 5 need not be limited to perforations. For example, the same effect can be obtained by forming a thin and long film of a colored fluororesin by welding.
Also, the direction of the line 5 is generally perpendicular to the running direction of the conveyor, but even if it has a slight angle to this direction, if it is parallel and equidistant, it can be expected that the load to be arranged will be a uniform arrangement. Similar effects can be obtained.

In the conveyor, several kinds of objects to be heated need to be heated for each lot. In that case, the object to be heated may be placed according to the mark corresponding to each type. For example, when a yarn is used as a mark, it is possible to correspond to each type by returning the thickness, color, and configuration of the chain line of the yarn.

Further, a mark is provided on a heat-resistant and moisture-resistant film according to each type of the object to be heated, and the film is attached to a conveyor belt when the object to be heated corresponding to the type is heated. You may.

Further, when heating is to be performed in a state where a plurality of types of objects to be heated are mixed, a mark is provided so that the load (object to be heated) in the furnace is constant, and a type of the object corresponding to the mark is provided. It is advisable to place a heated object.

[0025]

As described above, according to the present invention, the loads can be arranged at equal intervals on the conveyor belt, and the intervals can be maintained even after a lapse of time, and uniform heating of the loads can be realized.

The direction perpendicular to the running direction of the belt is relatively easy to arrange evenly because the throwing person can see the whole, but the running direction enters the inside of the tunnel as soon as it is thrown, and the space between front and rear is narrow. It is difficult to keep the interval constant over a long period of time because it can only look around. In this respect, since lines are drawn at equal intervals, uniform arrangement can be easily realized by arranging the load using this line as a guide.

[Brief description of the drawings]

FIG. 1A is a plan view of a continuous tunnel type microwave furnace according to one embodiment of the present invention. FIG. 1B is a side view of the continuous tunnel type microwave furnace.

FIG. 2 is a plan view of a connection portion of the conveyor belt according to one embodiment of the present invention.

[Explanation of symbols]

 1 furnace 4 conveyor belt 5 lines (mark)

Claims (4)

[Claims] 1. A furnace equipped with a microwave irradiation source for heating an object to be heated, and a conveyor belt on which the object to be heated is placed and which passes through the furnace, wherein the state of placing the object to be heated is provided. In order to be able to easily recognize the above, a tunnel type microwave continuous furnace configured to provide a mark on the surface of the conveyor belt. 2. The tunnel type microwave continuous furnace according to claim 1, wherein the marks are a plurality of equally spaced lines provided in a direction perpendicular to the traveling direction of the conveyor belt. 3. The tunnel type microwave continuous furnace according to claim 2, wherein the equally-spaced lines are formed at perforations. 4. The continuous microwave oven according to claim 2, wherein both ends of the conveyor belt are joined to form a loop, and a distance between the joined portion and an adjacent line is equal to a distance between the lines. .