JPH02223186A - Microwave induced heating and its apparatus - Google Patents

Abstract

PURPOSE:To heighten drying ability for electric consumption by heating an object to be heated by microwave while the object is kept declining against an electric field. CONSTITUTION:A slot (b) is formed in a narrower plane, an H' plane, of a rectangular box which is stopped expanding and an object to be heated which is inserted to the box is kept declining against an electrically charged plane E' generated by an electric field E. The electric field of a microwave is always perpendicular to rectangular cross-section of the wave guide tube and rectangular to an inner plane. The method to make the object declining to the plane E' is to decline a conveyer, a hollow tube, or a mold for transfer, which passes the H' plane and is made of a material with low specific dielectric loss coefficient and passes, or decline an applicator itself, or both of them. By this method, absorption of microwaves is heightened and energy loss is lowered, and drying ability for electric consumption is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a microwave heating method and an apparatus therefor.

More specifically, the present invention relates to a method for constrained heating of a heated object adjusted to a quasi-bound water region using microwaves, and in particular, in response to a microwave electric field, the constituent water of the heated object is reduced to other constituent material components. The object to be heated is shaped into a quasi-bound water region so as to be constrained by the waveguide, and after the rectangular waveguide is expanded one after another, the expansion is stopped and the applicator is made into a rectangular tube shape. The present invention relates to a microwave heating method and an apparatus therefor, which can increase the microwave absorption efficiency of a dielectric material adjusted to a quasi-coupled water region and uniformly dielectrically heat the dielectric material.

(Prior art) Regarding microwave heating of a dielectric material in the form of an O/W emulsion, the present inventor has previously discovered that microwave heating of a material to be heated containing a large amount of free water with the largest value of dielectric constant is It is the same as heating free water of the same size regardless of the constituent components of the body, and we focused on the fact that removing or evaporating free water simply wastes latent heat and time by reducing radio wave energy below 100"C. If the object to be heated (hereinafter referred to as the object to be heated) is adjusted to the quasi-bound water region from which free water has been almost completely removed, and then dielectrically heated, the amount of microwaves supplied will exceed the latent heat. The energy immediately generates high bound heat,
He discovered that it was possible to raise the temperature of a single product to 120°C or higher, which was previously unknown, even under normal pressure, and proposed a microwave constrained heating method for various semi-bound water regions (Patent No. 11°8095). ), L However, this heated object has a small amount of free water, which is the largest dielectric material for microwaves per unit area, and is mostly semi-bound water bound from the constituent material components. Due to their structure, the absorption efficiency of microwaves is relatively low for large-scale materials, but the absorption efficiency is even lower for materials with a large specific surface area, and a large microwave energy loss occurs due to heat dissipation. In order to solve these problems, the present inventors have previously studied various methods mainly based on the behavior of water in microwave electric fields. On the other hand, from the perspective of the structure of the applicator and the feeding method, we have pursued methods to further maximize the microwave characteristics of the heated object, and as a result of intensive research, we have made these proposals. Most of the difficulties are due to the structure of the heating section applicator and the method of supplying the object to be heated, and it was discovered that this problem could be solved by placing the object to be heated obliquely in the electric field, leading to the completion of the present invention.

As in the present invention, a successively enlarged pyramidal waveguide is used to heat the heated object obliquely with respect to the electric field using microwaves. The method of preventing unevenness is based on a completely different principle from the conventional microwave heating using a fan, diffusion, rotation, etc., and is a new technology unknown to the present.

(Problems to be Solved by the Invention) The structure and characteristics of conventionally known applicators are as follows: (1) Box-type applicators, as symbolized by microwave ovens, are batch-type, so they are not continuous and have size limitations. . (2)
In the continuous tunnel type and its combination type with external heating, pressure, etc., a waveguide is connected to a tunnel type applicator with a large specific volume to supply and diffuse microwaves. It is easy to cause non-uniformity and has many loss factors, so the microwave energy efficiency tends to be low, and the initial equipment is expensive, making it difficult to use in a wide range of fields. (3) In the case of the waveguide slit incidence type and its multiple diagonal and folded types, the microwave is strongly absorbed on the input side due to the strong electric field, making it difficult to heat the output side and causing uneven heating. The size of the object to be heated is limited by the size of the waveguide slit, which has the disadvantage of lack of versatility. (4) In the example of a biramidal horn type that applies an electromagnetic wrapper for a directional antenna, it is possible to reduce the initial size of the equipment in (2) and expand the size of the heated object in (3). In the conventional method of dielectric heating perpendicular to the direction, cloth-like sheets or strings such as fibers that contain a large amount of free water and have relatively high microwave absorption in the free water region in terms of microwaves are used. Applications are limited to objects to be heated, such as materials like this one, and in microwave terms, free water has been removed, such as in this heated object, where water is molecularly strongly constrained from the weak colloidal constraint of the quasi-bound water region. The dielectric material subjected to the heating has extremely low absorption of microwaves, so it becomes difficult to generate heat, resulting in large energy loss, and it is not possible to eliminate heating unevenness, making it ineffective. The aim is to overcome one or more of the drawbacks mentioned above.

(Means for Solving the Problems) First of all, the material to be subjected to microwave heat treatment by the method of the present invention, that is, the object to be heated, has a moisture content adjusted to a semi-bonded moisture region in which free water has been removed as much as possible. It was done. It must be composed mainly of hydrophilic polymeric organic colloids, but an example of this is a slurry-like product made by kneading a liquid and powder or concentrating a liquid.

Alternatively, it may be in the form of a semi-dried pellet, or it may have an emulsion composition mainly composed of cell membranes from which interfascicular free water has been desorbed.

Further, depending on the necessity of the desired effect, there is no problem even if inorganic salts or the like are added and dispersed therein as a medium. In short, most of the free water has been desorbed, and the water content has been adjusted to a semi-bound water region ranging from strong molecular constraints to weak colloidal constraints from constituent molecular components other than water. That's fine.

There are various methods for determining the quasi-bonded water region in the microwave electric field of this heated object, including simple methods using a microwave oven, but to determine the accurate range, it is necessary to measure the dielectric constant under two or more different electric fields. Then, the maximum and minimum values can be easily determined from two points of inflection that are constant at the slope of the curve.

When microwaves are applied to this object to be heated, the water is bound to other constituent molecules at various rates ranging from strong bonds to gradual colloidal constraints, so the dipoles of the water change in response to the electric field. It orients itself inconveniently depending on the degree of constraint. Due to its binding, the incident microwave energy loses latent heat at a low rate, and the excess energy that has no way to escape, called latent heat loss, is accumulated as heat in proportion to the excess rate. Instantly 1
The product temperature is raised to 20°C or higher, the temperature gradient becomes rapidly linear, and the product is dried to a low moisture level in about 3 to 40 seconds, completing the entire heating process. Therefore, depending on your needs, for example, by supplying microwave energy while reducing it to a lower rate commensurate with the latent heat, and taking advantage of the depth of reach that is a feature of microwaves, for example, you can create a thick object that contains an aerosol that does not absorb radio waves. There is no problem even if only gelation is achieved at low temperature.

The shape can be freely selected according to desire. For example, the slurry may be deposited on a conveyor, the slurry may be filled into a Teflon film or tube with a low dielectric constant, and the slurry may be solidified and fixed by microwave heating, or the molded product may be sealed in a Teflon mold. You can freely adopt methods such as preforming to complete the molding by expanding and fixing it in the shape of the mold using microwaves.

The basic structure of the heating part applicator in the present invention is described above (
2) In order to eliminate the drawbacks of the conventional type (3), a pyramidal horn type is adopted in which the rectangular waveguide of (4) is sequentially enlarged into a pyramidal horn shape. A type that is simply expanded into a sequential pyramid shape or an exponentially changing trumpet shape is fine, but since the microwave has the property of being perpendicular to the conductor surface, the proportion of oblique intersection with radio waves will be reduced in the expanded section. There are disadvantages and the conveyor width is narrow because the size is limited in the pipe.

Since energy loss on the wide side is unavoidable, the present invention employs an applicator that is sequentially expanded into a pyramidal shape and then stopped from expanding into a rectangular tube shape. A feature of the present invention is that a slot is provided on the narrower side of the rectangular tube-shaped part, which has ceased to expand, on the H' side, so that the object to be heated, which is inserted through it, is placed on the wide side E', which is charged by the electric field E. It is oblique to the other. Although the microwave electric field is always perpendicular to the orthogonal cross section of the waveguide and perpendicular to the internal surface, the present invention clearly differs from the conventional microwave heating means in which the electric field component direction is perpendicular to the waveguide. They are different. The oblique method is made of a material with a low value of specific induction loss coefficient. A conveyor or hollow tube that penetrates the H′ plane,
This is accomplished by tilting the conveyor part such as the mold, the applicator tube itself, or both.

FIG. 1 illustrates the above-mentioned conventional microwave heating device which is oriented perpendicular to the electric field component direction.

Figure 1 shows a rectangular waveguide whose narrow H-plane and wide E-plane are sequentially enlarged to form a pyramidal wrapper C-plane to form a pyramid-shaped open structure. The H plane and the E plane form an H' plane and an E' plane, respectively. In Figure 1, the heated object (inlet side is a, outlet side is a)
A slot portion (the entry side position is shown as b and the exit side position is shown as b') through which the slot (indicated by b') is inserted is formed on the H' surface.As is clear from Fig. 1, in this conventional device, The object to be heated faces perpendicularly to the direction of the electric field e.

FIG. 2 shows an embodiment of the device according to the present invention, which is not an orthogonal type like the conventional device, but a diagonal type. In other words, the installation positions of the slot portions on the H' plane after enlargement, that is, the entry side position and the exit side position b', are not set on the same horizontal plane as in the past, but are set at different heights, and The object to be heated is provided obliquely to the E' plane.

The oblique angle to the E' plane is when the width of the H' plane is 300 m.
11, preferably 5 to 50 on the inner surface of the tube in order to maximize the radio wave characteristics of the microwave.
It penetrates at an oblique angle of 100 degrees. Compared to the method in which the angle is perpendicular to ε', the effect of improving the microwave absorption rate starts to appear from around 3 degrees, and the most effective is from 5 to 50 degrees.
At 50 degrees or more, the effect did not increase much and tended to be slightly attenuated. However, the range of this angle is not necessarily limited to the above range, and depends on the organization, structure, and composition of the molded object to be heated, the swelling state during heating, the size after molding and fixation, and the shape of the molding frame. The relationship between the size and the size of the H' plane may be changed as appropriate depending on the purpose of heating, workability, etc.

In addition, in the present invention, another qualitative oblique condition that is not particularly limited by the width size of the H' plane is:
When the object to be heated passes through the surface of the applicator 87, the height difference between the entrance side and the exit side on the inner surface of the tube can be 1/4 or more of the wavelength of the microwave. The high effect is in the range of 1/4 to 1 wavelength, and the highest effect is at about 172 wavelengths, which can also be said to mean that even if the wavelength is -wavelength or more, the effect does not improve to H.

According to the present invention, the drying efficiency is greatly increased by forming the oblique pattern, and although the detailed mechanism will require further research, it is estimated as follows. In other words, the reason why radio wave loss is lower and heating unevenness is significantly reduced when crossing obliquely than perpendicularly is probably due to the relationship between wavelength, standing waves, half-reaching depth, etc. (Neither at right angles nor parallel to the magnetic field), it is also closely related to the fact that the polar molecules of the object to be heated cannot freely orient themselves in the electric field like free water, making unfree orientation movements. Therefore, it appears that an increase in the absorption distance beyond the position where the standing wave occurs significantly improves the radio wave absorption rate of semi-coupled water.

The shape of the portion C in which the rectangular waveguide is sequentially enlarged can be used by sequentially enlarging the four walls or by sequentially enlarging only the H planes facing each other. The successively increasing length is too long and the loss of microwave attenuation is extremely small compared to the effect obtained by the present invention.
Rather, the length is determined by the length that provides the optimal effect, i.e., productivity and quality of workmanship, in accordance with the opening angle, and the cross section required for heat treatment is determined depending on the size of the object to be heated. In the case of a 0-wire heated object, as the length increases, the heating efficiency tends to be improved by reducing the opening angle and using a strong electric field with less unevenness. In addition, until the length reaches the optimal opening angle, it depends on the microwave output per unit area, but since the longer the length, the more effective it is to prevent uneven heating, In order to obtain the effect, the opening angle must be reduced.

The effect was observed when the enlarged opening angle was 3 degrees or more. For this object to be heated, the most excellent effect was obtained when the opening was selected from 5 to 50 degrees, and when the opening was 51 degrees or more, the radio waves were too diffused and the effect did not increase. Industrially, the most preferred one was one in which the transition from the waveguide to the expanded space was not abrupt, and the opening angle was gradually expanded to about 4 to 35 degrees. However, the angle of expansion can be freely selected because the opening angle of the applicator is determined by the desired electric field strength and the characteristics, size, and shape of the object to be heated.

For example, if you want to increase the degree of foaming and swelling of the object to be heated, you can adjust the opening angle at which the surface E sequentially expands to a low value, and if you want to prevent foaming and swelling, you can adjust the opening angle to a high value to obtain the desired degree of expansion. be.

Furthermore, the opening angle of the H surface needs to be adjusted to the optimum angle depending on the binding strength of the water of the object to be heated, and since an applicator with a fixed angle is not versatile, a movable shielding plate g is installed to By adjusting the incident width of the machine, it is possible to produce a wide variety of products in small quantities with a single model, and it is possible to maintain versatility not found in conventional industrial production machines.

This movable blocking plate can also be applied to the opening angle of the above-mentioned E plane, further improving the versatility of the present invention.

An example device provided with this movable blocking plate g is illustrated in FIG. A pair of movable shielding plates g are provided at the connection portion between the pyramidal wrapper portion C and the plane E', but the number and location of the movable shielding plates g may be determined as appropriate without particular limitation. Further, the movable blocking plate g may be movable, or if it is used only for a specific purpose, it may be fixed at a predetermined angle that provides the best results. Furthermore, the fifth
In the figure, d is a movable bottom puller attached to the bottom,
It performs matching of reflected waves.

(Movable reflector) The inclination angle and/or height of the movable bottom plate d can be changed freely according to the purpose, but if desired, it can be fixed in the same way as the movable plate g. You can also.

A device of the type in which the movable blocking plate g is removed from the embodiment device shown in FIG. 5 is shown in FIG. 4, in which (A) is a sectional view and (B) is a partially cutaway view. FIG.

The apparatus of the present invention described above with reference to FIGS. 2 and 4.5 is of the type that uses a single tube. However, the device used in the present invention can not only utilize a single tube, but also connect the H' side of a plurality of tubes. A single tube alone cannot do more work than the microwave output of the connected oscillator, so the amount of heat processing is limited by the output of the magnetron, and the equipment initial may limit industrial profitability. It is.

FIG. 3 shows an example in which a plurality of single pipe bodies are connected and utilized.

(A) in the figure shows a type in which the object to be heated is moved horizontally (therefore, the tube body itself must be tilted while connecting the H' side) (B) in the figure.
This figure shows a type in which a plurality of tube bodies are made to stand upright while connecting their H' sides (therefore, the object to be heated is inclined).

Examples are shown below.

Example 1 A viscous egg slurry with a water content of 34% in the semi-bound water region was prepared by emulsifying liquid whole eggs and whole egg powder with oil and fat, and dispersing caster sugar, salt, chemical seasonings, and starch therein. This material is deposited in the form of 0.4 g/piece on a moving Teflon-impregnated glass wool conveyor, and the microwave output is 4 kW.
10 magnetrons were aligned and applied to a tunnel-type applicator. The finished product had the appearance of a yellowish-white egg and had expanded evenly and evenly, but the object to be heated was in the region of semi-bonded water that was relatively strongly constrained, and the diameter of the egg particle was too large to be exposed to microwaves. As a heating object, it is fine and has a large center pitch, so it is close to the limit for absorbing microwaves and heating and expanding, but the microwave energy efficiency is extremely low, which is a problem. The average rate of occurrence of reflected waves inside the waveguide during processing is approximately 34% even when matching is performed using a power monitor, and the energy efficiency of the oscillated radio waves is also low at approximately 26%. This indicates that the loss was also caused by various equipment loss factors such as various parts of the applicator, cooling water, and absorption traps.

Next, in hopes of producing a heating effect in a strong electric field, we connected an oscillator using a magnetron with a microwave output of 1.6 kW as shown below into a waveguide enlarged trumpet type applicator for microwave heating, and conveyed continuously. and dielectrically heated. The applicator sequentially expands a JIS standard rectangular waveguide in all directions at an opening angle of 18 degrees, and the terminal stops expanding and forms a rectangular tube wall with one side of the E' plane being 700+ am and one side of the H' plane being 3501111. , a length of 230 mm on the H' plane of the rectangular tube body,
A slit section with a height of 20 m is provided, an absorption edge trap section is provided on the outside to prevent microwave leakage, and a movable bottom hole is installed at the bottom to enable matching of reflected waves. A movable plate g was provided at the portion where the surface and the H' surface connect to make it possible to adjust the width of incidence of microwaves (hereinafter abbreviated as the present device).

Initially, the moisture content is in the free water region of 67%, and the temperature is 45°C.
Atohair glue (made by Sekisui Resin), which has the property of turning the transparent liquid cloudy when the temperature rises above this level, is applied to the entire surface of the conveyor to a thickness of 1 m1.
When the sheet was formed into a sheet of No. 1 and inserted perpendicularly to the E' plane, the entire surface became uniformly cloudy and no uneven heating occurred.

This condition was the same even when the shape was made into the egg-like shape, and the radio wave absorption rate was as high as 89%.

Next, when the egg grains of the object to be heated in the above-mentioned semi-bound water region were fed and passed in alignment with a center pitch of 0.8 mm perpendicular to the E' plane, the obtained product was fed in the direction of movement of the belt conveyor. On the other hand, only the width of about 30 mm at the center was denatured by heat and became a scrambled elag with a yellowish white diameter of around 71 which was close to the peak of swelling, but the egg grains of 90 mm each at both ends were heated unevenly. In this state, some unfoamed material was mixed in, the edges were hardly denatured by heat, and the center pitch remained the same, making it a dark reddish-colored dough that could not be made into a product. You can adjust the energy density by changing the belt speed.

Even after adjusting the movable bottom removal and measuring the matching, when measured with a power monitor, the reflected wave value reached 49-60%.
Not only did it not have the effect of a strong electric field, but the workmanship was poorer than that of the tunnel type, so it could not be used as a product.

Next, an air-cooled oscillator with a microwave output of 1.5kW and a 4kl/
The waveguides of the water-cooled oscillators were connected to this device separately and matched in the same way. In both cases, the condition is the same as that of a 1.6Nl oscillator, and even if you measure the matching or adjust the movable shield plate g, the workmanship does not improve, and depending on the difference in output per unit area and heating time, uneven heating may be prevented. It was confirmed that there was no effect of increasing the amount of processing or processing, and that radio wave loss was also increasing.

Therefore, as shown in FIG. 4 (and by further providing a movable plate g as shown in FIG. 5), the height difference between the center of the opening on the inlet and outlet sides provided on the surface of the water device E' is set to 30+am. year,
The inclination angle of the conveyor passing through the opening is set to 4.9 degrees, and the egg particles are passed through, giving a microwave output of 1.3, 1.5
k17.4. Microwave heating was performed using an OIW oscillator. The resulting product had a throughput that corresponded to the output, and the egg grains that could not be achieved with the orthogonal method expanded evenly and uniformly over the entire surface, resulting in a product with the appearance typical of scrambled erag. At this time, the values of reflected waves had all decreased to 25% or less.

Furthermore, the voltage was applied by varying the height difference.

The microwave absorption rate is highest when the height difference between the input side and the output side is around 6011ffi, and the radio wave absorption efficiency is 92%.
reached. This difference in height almost corresponds to the 172 wavelength of microwaves, and it was also found that even if the slope was increased, the absorption rate would not be higher than this. In addition, even if the slope, which is the difference in height between the exit and entry sides provided on the H' plane, was made obliquely downward or at an elevation angle, the same high and even absorption effect was obtained. It turns out that things work.

Even if the height difference was increased by one wavelength or more, the steep slopes of the pipes and conveyors would only make production more inconvenient, and the heating efficiency would not increase any further. The absorption efficiency was higher when multiple tubes were connected as shown in Fig. 3 than when they were made into a single body, but this was judged to be due to a reduction in the leakage absorption loss portion.

Next, when the water content of the egg dough was reduced to 28% and the diameter of the egg grains was increased to 0.8 g/piece and dielectric heating was performed in the same manner, the degree of swelling was large in the center and small at both ends, resulting in uneven swelling. Lower the opening angle of the H side and make the width of the H' side 280mm.
When the diameter was narrowed, it was able to expand almost uniformly. Furthermore, as the opening angle of the E plane was lowered and the length of the E' plane was shortened, the swelling ratio increased. However, due to the moisture content, the shape of the egg grains, and the alignment pitch, we determined that it was not possible to use a dedicated regular opening device for each case, so we fine-tuned the movable shielding plates g provided on the E' and E' faces, and found that the H When the entrance width at the tip of the movable blocking plate was adjusted to be approximately the same as that at the open end of '.

Example 2 Product temperature adjusted to slightly strong semi-bound water region with moisture content of 33% by emulsifying and mixing heated and melted cheese at 70%, milk protein peptides at 18%, and seasonings at a dry weight ratio of 12%. 40
℃ cheese curd was formed into a sheet with a thickness of 0.3 degrees Celsius on a conveyor, and then heated at a sequentially expanding opening angle of 25 degrees using the microphone A-wave device of Example [1].

When the conveyor was first heated perpendicularly to the E' plane with the conveyor stopped, striped burnt areas and unheated areas occurred every 30 or so blocks, resulting in failure to produce a product. This unevenness of the standing waves was not much improved even by adjusting the angle and distance of the movable reflector at the bottom.When the zero-order conveyor was driven, the sheet-like molding of Athair glue with free water was uniformly cloudy. Since this cheese curd had no free water, the central portion of about 45 mm foamed and swelled in a wrinkle-like white color, and both sides remained as a translucent slurry and could not be made into a product. However, when the conveyor angle is made oblique to the E' plane as shown in Fig. 2, the absorption of radio waves is significantly improved as in Example [1], reaching a maximum near the height difference of 172 wavelengths, and decreasing at more than 1 wavelength. The results did not improve any further.

A slurry prepared by adding sugar alcohol to the egg dough of Example [1] to adjust the water content to a semi-bound water region of 26% was molded as described above and dielectrically heated, resulting in a thickness of 0.7 in the center.
The thickness was 0.7 mm at both ends of 3 mm, resulting in uneven thickness. Therefore, the angle of the movable blocking plate d on the E' plane was adjusted narrowly to obtain a long sheet with a uniform thickness of 0.8+am as a whole.

In this state, whether it is an electrolyte-rich umeboshi-based curd adjusted to a semi-bound water region with a pH of 3 to 4 and a moisture content of 36%, or an orange-based emulsion containing sugars as its main component, the orthogonal In this case, the effect was significantly increased when it was not a product but was crossed obliquely. In addition, for various thin films of the object to be heated, conventionally, the tunnel type described in (2) above could only achieve a microwave energy efficiency of around 25%, but when implemented with the present invention, the average efficiency was 83%, which is high. Efficiency was achieved.

Example 3 Glutinous rice and waxy starch gelatinized by a conventional method were lined and dried to form a size of 15 x 50 x 2 a + m, with a moisture content of 17 to 24%.
Make the rice cracker dough in the semi-bound water area, and set the conveyor part to 4.
It was supplied to the apparatus of Example [1] above, except that the caterpillar-type double Teflon plate heated to 0°C was used. The upper surface of the lower part of the Teflon plate was shaved to a size of 200 x 50 x 5 am to form a mold into which the rice cracker dough was inserted, and when the top and bottom were put together, it could be almost sealed, with pores for steam leakage at the four corners. In a product in which the molded caterpillar conveyor was orthogonal to the conductor surface, the double layer in the center was foamed and expanded to the full extent of the mold, but unfoamed portions remained at the four corners and were hard and defective. The dough on both sides hardly puffed and did not become a product.6 Next, when we tilted the caterpillar conveyor, the dough on both sides gradually became more uniformly puffed, and when we reduced the drop in and out to 1/4 wavelength, everything became uniform. It expanded evenly. When the slope was increased further, the maximum float was observed when the head difference was around 172 wavelengths, and little change was observed at higher slopes. All of the products were foamed and expanded uniformly in the mold and all the way to the four corners.

Example 4 Add defatted whole soybeans, young cloth powder, chopped stems, kelp, black sesame seeds, nuts, chopped onions, carrots, dried shrimp, salted sea urchin, cacao trout, to the dough of Example [3] as ingredients. Formed dough mixed with cheese, etc., or seasoned with thin fresh leaves on the surface of the formed dough of Example [3], or dried such as artichoke, tsurumurasaki, saisin, chopped pumpkin, watercress, shungiku, and basil. When thin pieces of vegetables such as spring, mugwort, fragrant vegetables, wild plants, and medicinal herbs were placed or sandwiched together and dielectrically heated at various oblique angles, uneven swelling occurred on the orthogonal conveyor as in the previous example, and the product was not formed. There wasn't, though.

If the height difference was between 1/4 and 1 wavelength, all the products showed smooth flow and the flavor and color of the added ingredients and greens were fully utilized.

Example 5 Mixed surimi was prepared using 50 parts of shrimp surimi, 30 parts of walleye surimi, 10 parts of egg white, 5 parts of tapioca starch, and 5 parts of seasoning, and a hollow curved peeled shrimp-shaped hole was provided in the cross section. Press the surimi into a Teflon tube to make 1 kg of Power Densty.
/ 1 kW to solidify by microwave heating. After freezing, this was cut into 3m-wide pieces, air-dried, and made into chips with a relatively strong semi-bonded water region with a moisture content of 23%.The chips were packed into a tray in the present device shown in Example [1]. When microwaves were applied at right angles to each other, a shrimp-like product was obtained that was white, round, and foamed only in the center, but as it approached the edges, the expansion peak did not reach the peak and the shrinkage expanded unevenly due to residue. It only warmed up to about 60 copies, but there was no change at all and it was not made into a product.

Next, when the tray was tilted diagonally and voltage was applied, the entire surface of the tray expanded uniformly and evenly from an angle of inclination of around 5 degrees. The maximum float was around 20 degrees. Next, as shown in Fig. 3 (B), the head between the entrance and exit of one tube of this device is 2
With 75 wavelengths, 5 tubes are connected in a stepwise manner, and the input P, D,
When the microwave output was expanded at the same rate and diagonally crossed while attenuating at the rate of 1 → 1 → 0.8 → 0.5 → 0.3 toward the output side, it was found that there was no unevenness in the same way. An emulsified dry product was obtained, and the production efficiency per microwave output was increased. With this connection method, the final outlet was high and production operations were somewhat inconvenient, so as shown in Figure 3 (A), the pipe body was
When the five pipes were connected on the H' side at an angle of inclination and the tray conveyor was placed almost parallel to the floor, the operation was easy and the results obtained were exactly the same.

In the same way, if you replace the shrimp surimi with peeled purple squid surimi, mold it into the shape of a dried squid, and heat it with microwaves, if you place them perpendicularly in the same way, it will not become a product, and you will not be able to make a single pipe or connection. When the tube was used to pass through the molded article obliquely, it expanded evenly and uniformly, and the loss of reflected waves was reduced to 1/3.

Example 6 Chicken minced meat partially peptized with protease 7
O/W at a ratio of 0%, ester starch 5%, seasoning 25%
A molded card was made, and this was extruded through 20 parallel nozzles to form a stick shape with a diameter of 5IIIll, which was denatured and fixed by heating with steam, and then air-dried to form a chicken in the semi-bound water region with a moisture content of 36%. I made it into a stick. When this was placed perpendicular to the device of Example [1] and dielectrically heated, the central part was heated strongly after 12 seconds and the moisture 6
%, but the edges were hardly heated and the moisture content was 35%, making uniform drying impossible with orthogonal drying. Therefore, when dielectric heating was performed diagonally while changing the head of the entrance and exit under the same conditions, when the height difference between the person and the exit was more than 1/4 wavelength, the temperature of all the products instantly reached 120℃ or more, causing evaporation. After 5 seconds, the resulting product was a foamed chicken stick with a moisture content of about 15%, which was puffed softly and uniformly.

Example 7 After mixing a sugar alcohol and an amino acid compound, amyl alcohol was produced using yeast and subjected to a condensation reaction with an organic acid to biosynthesize a complex ester.

This substance is candy-like and has a moisture content of 34%, which is in the semi-bound water region.
The average number of viable bacteria was 10+s/g. This was uniformly pressure-fed into 25 10 m track diameter 0 Teflon tubes inserted into this device and dielectrically heated. In the conventional orthogonal method, the 18 wires in the center emit strong bound heat and emit heat, gradually becoming less heated toward both ends, and the edges are only slightly warmed. The number of viable bacteria after heat treatment is <1 in the center.
It decreased to 0''/g, but the rate of decrease decreased as it approached the edge, and at the edge, it was IO + 7/g, only heat-sensitive yeasts were sterilized, but heat-resistant bacteria did not decrease at all. Using the oblique method, all 25 tubes generated a confined heat of 125°C in 3 seconds with the same output and flow rate, and flowed out uniformly from the tip of the tube.The resulting products all had a water content of 29%. The number of viable bacteria was <30 cells/g, which was close to sterile, and the composite ester was hardly destroyed at an activity rate of 94%, so it was confirmed that the desired activity was maintained.

Example 8 Thin slices of beef red meat are immersed in a highly concentrated seasoning solution to remove interfascicular free water using curing and osmotic pressure, and then the surface liquid is removed to remove mainly semi-bound water from intracellular colloids. The seasoning was adjusted to the desired area by making beef pieces, placing them all over the Teflon net conveyor in the device of Example [1], and forcing hot air at 3% humidity and 50°C from the exit side to the input side. The power density steel was dielectrically heated at a low power of 2 kW/kg while transmitting the light. In the case of the belt obtained by orthogonally crossing the belt, even though the central part of the belt was strongly heated and scorched and shrunk, the edge part was undenatured and did not shrink, and the surface was only slightly dried by hot air. Next, when heating was performed in the same manner with the exit side 1/2 wavelength lower than the input side, the beef was heated evenly and had a slight shrinkage throughout, resulting in uniformly seasoned dried beef.

Example 9 Pork that has been refrigerated and seasoned and cured is cut into particles of about 3 mm with as little disruption of cell membranes as possible, kneaded, shaped into round particles with a diameter of Low-, and dried with low-humidity cold air to make free water. was almost completely removed to adjust the moisture content to a semi-bound water region of 35%. Next, it was supplied to the thin tray conveyor of the present invention to a uniform thickness and dielectrically heated at P, 0.8. In the case of the meat obtained by crossing at right angles, the red meat was heated strongly in the center and dried and solidified, and the fat membrane burst and separated, but as it approached the edges, it became difficult to heat and became undenatured, resulting in the product. did not become. Next, when we tilted the tray conveyor with a difference in entrance and exit, the heating unevenness decreased from around 175 wavelengths.
When the difference was 4 or more wavelengths, it became almost uniform, and when the difference was 1/2 wavelength or more, no solidification or separation occurred, and it expanded uniformly, with no unevenness at all.

(Effects of the Invention) According to the present invention, a novel configuration has been adopted for the first time in which the object to be heated is not heated by microwaves while being perpendicular to the electric field as in the conventional method, but is heated by microwaves by placing the object at an angle to the electric field. By doing so, the drying processing capacity relative to the amount of electricity used can be greatly increased.

Further, according to the present invention, as described above, the sequential expansion type (4) is heated in the applicator in which the waveguide is actually expanded sequentially in the same manner as the waveguide heating (3). Therefore, compared to other conventional connection type applicators, the equipment is simple and the electric field is strong, so the radio wave efficiency is good, so the equipment initial is inexpensive, but because the electric field is applied perpendicular to the object to be heated, However, as mentioned above, there are disadvantages in that uneven heating occurs and the specific absorption efficiency of microwaves is low. Most of these problems can be solved by arranging the object to be heated obliquely with respect to the direction of the microwave electric field component as in the present invention.

The microwaves that are not absorbed by the above-mentioned types (2) and (3) cannot avoid the generation of reflected waves when it comes to the object to be heated. Since the microwave energy is separated using a rotating isolator or circulator and absorbed by the load, it was inevitable that a considerable amount of microwave energy would be lost.

In (4) above, the reflected waves are matched by adjusting the movable reflector at the end of the tube, but the oblique results show that the microwaves are absorbed extremely efficiently and almost no reflected waves are generated. Therefore, almost no microwave energy loss occurred. Therefore, in the present invention, the microwave loss is reduced by about 6 to 70% compared to the conventional method, the processing capacity is significantly improved, and the energy saving effect is enhanced. In addition, according to the present invention, heating unevenness does not occur at all even in the case of the object to be heated in the region of strongly semi-bonded water, which cannot be finished as a product due to obvious heating unevenness in the center and edges in the orthogonal type.
Another feature is that it can be made into a uniform product.

In the present invention, the opening angle, expansion length, and diagonal feeding penetration angle can be freely determined depending on the shape size and characteristics of the object to be heated, and the desired effect. As shown in FIG.

Therefore, the present invention can be widely used for drying not only foods but also medicines and all other substances, and can also be used for sterilization.

[Brief explanation of the drawing]

FIG. 1 shows an example of a conventional orthogonal type. Fig. 2 shows an oblique type connection according to the present invention.6 Fig. 3 shows an example of an oblique connection according to the present invention, and (A) shows a plurality of H'
This figure shows a type in which the pipes are connected by a plane, and (B) shows a type in which a plurality of pipes are connected by a plane H' in a stepwise manner while the tube bodies are kept upright. FIG. 4 shows an example of the device of the present invention shown in FIG. S, with the movable blocking plate removed. (A) is a sectional view thereof, and (B) is a partially cutaway perspective view thereof. FIG. 5 illustrates an example of an oblique type according to the present invention. In the figure, E indicates the E plane before enlargement, E' indicates the E plane after enlargement, H indicates the H plane before enlargement, H' indicates the H plane after enlargement, a indicates the entrance side of the object to be heated, and a' indicates the exit side. b indicates the entry side position of the slot portion, b' indicates the exit side position, C indicates the pyramidal wrapper portion that gradually expands, d indicates the movable bottom, and g indicates the movable blocking plate.

Claims (1)

[Scope of Claims] 1. A material to be heated which is formed by adjusting the semi-bonded water region so that water molecules of a material mainly composed of a dielectric are bound by molecules of other constituent materials in a microwave electric field. , the rectangular waveguide gradually expands into a pyramidal trumpet shape, and then an entry/exit slot section with a height difference is provided on the H' plane where the expansion has stopped, and the object to be heated is diagonally crossed with respect to the E' plane, and the dielectric A microwave heating method characterized by heating. 2. The microwave according to item 1, wherein the microwave is diagonally crossed on the output side at a position of 1/4 wavelength or more with respect to the input side of the H' plane, thereby moving and penetrating the object to be heated in an oblique direction. Heating method. 3. At the part where the pyramid-shaped wrapper becomes a rectangular tube shape, hold multiple applicators at an angle of H' without tilting or tilting them.
2. The microwave heating method according to claim 1, wherein the object to be heated is connected on the surface side, and the object to be heated is made obliquely perpendicular to the E' surface, so that the object is moved and penetrated in an oblique direction. 4. Using a waveguide that expands sequentially, the degree of foam expansion is increased by adjusting the expansion angle of the E plane to a low value, and the degree of foam expansion is decreased by adjusting the angle to a high value. Microwave heating method described in Section. 5. The microwave heating method according to item 1, characterized in that on the E plane that has stopped expanding, a movable shielding plate g is provided at the connection part between the C and E' planes to adjust the incident width on the H' plane. . 6. Sequentially expand the rectangular waveguide to form a pyramidal trumpet shape, then provide an entry/exit slot with a difference in height on the H' plane that has stopped expanding, and place the object to be heated diagonally across the E' plane. A microwave heating device characterized in that it is configured to perform induction heating.