KR20170084948A

KR20170084948A - low tempertature and vacuum dryer apparatus using microwave

Info

Publication number: KR20170084948A
Application number: KR1020160004410A
Authority: KR
Inventors: 황현태; 신종일; 신훈종
Original assignee: 지디티 주식회사
Priority date: 2016-01-13
Filing date: 2016-01-13
Publication date: 2017-07-21

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature vacuum drying apparatus using microwaves capable of highly efficiently drying an object requiring drying, such as vegetables, fruit, sludge, food waste, etc. More specifically, the present invention relates to an external chamber having an openable and closable lid; An inner chamber disposed inside the outer chamber, the inner chamber having a structure capable of passing water vapor while blocking external leakage of the microwave; A plurality of microwave generators for emitting a microwave into the inner chamber; A vacuum pump for evacuating the outer chamber and the inner chamber; And a heat exchanger installed in a space between the outer chamber and the inner chamber to remove heat of steam generated from the object to be dried by the microwave and to condense the condensed water.

Description

[0001] The present invention relates to a low temperature vacuum drying apparatus using a microwave,

TECHNICAL FIELD The present invention relates to a low-temperature vacuum drying apparatus using a microwave capable of highly drying an object requiring drying, such as vegetables, fruit, sludge, food waste, and the like.

Drying techniques such as hot air drying, freeze drying, and spray drying are used industrially, and an appropriate method is selected according to the object to be dried.

Any type of drying requires energy input and is time consuming to dry the dried object.

The most widely used hot air drying is about 30% energy efficiency, it takes a long time to dry, and when the object to be dried is vegetable, there is a problem of severe discoloration.

In particular, various vegetables, fruits, and grains which can be converted into food are inferior in storage property, so that it is necessary to dry them for storage and distribution.

In order to create a higher added value, it is necessary to dry the nutrient and the inherent color of the dried object so as not to discolor.

FIG. 1 is a cross-sectional view showing an embodiment of a drying apparatus for treating garbage according to the prior art, according to the prior art related to the present invention, which is disclosed in U.S. Patent No. 5,335,425.

The prior art includes a shielding container 1 made of a microwave blocking material, a garbage bin 2 having a heat insulating property for the charged garbage and having a space for allowing water vapor to pass therethrough, A microwave oscillator (4) for generating microwaves and radiating microwaves to the garbage contained in the garbage reservoir for heating the garbage, and a cooling circuit for cooling the walls of the shielding vessel to condense the water vapor discharged from the heated garbage And a temperature sensor (23) for detecting an internal temperature of the garbage reservoir and detecting a temperature of water vapor discharged from the heated garbage, wherein the temperature measured by the temperature sensor At the end of the drying process, the instantaneous heating and drying process exceeds the preset temperature reference point Is completed.

In the prior art, steam is generated by heating an object placed in a garbage bin using a microwave, and water vapor is discharged through a steam outlet 2a of the garbage bin 2 and then condensed on the inner wall of the sealing container 1 Drain pipe (7).

However, the prior art has a serious problem that adversely affects the drying efficiency.

Generally, a drying technique using a microwave is known to have higher energy efficiency than a drying technique using other methods. However, in the prior art, since the microwave is mounted outside the shielding container and discharged toward the garbage storage, It can not be utilized 100%.

In other words, the refuse reservoir 2 itself has to be permeated by microwave. Conversely, a part of the microwave that has permeated into the refuse reservoir 2 can be returned to the outside and absorbed into other components. Particularly, the problem is that the steam is generated due to the progress of the heating to some extent, and the water vapor escapes through the steam outlet 2a, and when the internal space 21 of the sealing container 1 is filled, the microwave is absorbed by the steam, Microwaves are also absorbed into the condensed water condensed on the inner wall of the container.

In other words, a significant amount of the input microwave is either absorbed in the water vapor or re-absorbed in the condensed water to vaporize the condensed water. For this reason, the drying efficiency drops sharply.

In addition, in the case of the prior art, the object is heated by the high-temperature drying method at a temperature higher than the breaking point of the water to generate water vapor. Therefore, when the object to be dried is vegetable or fruit, the surface is severely discolored or burned, which makes it impossible to use.

U.S. Patent No. 5,335,425

Accordingly, the present invention relates to a low-temperature vacuum drying apparatus using a microwave, which can maximize energy efficiency and minimize the change in nutrients and color of a dried object through low-temperature drying, &Lt; / RTI >

Further, the present invention aims to provide a high-efficiency low-temperature vacuum drying apparatus by increasing the cooling area where water vapor can condense by disposing a heat exchanger in a space between the outer chamber and the inner chamber.

The present invention provides a low temperature vacuum drying apparatus using microwave, comprising: an outer chamber having a lid capable of opening and closing; An inner chamber disposed inside the outer chamber, the inner chamber having a structure capable of passing water vapor while blocking external leakage of the microwave; A plurality of microwave generators for emitting a microwave into the inner chamber; A vacuum pump for evacuating the outer chamber and the inner chamber; And a heat exchanger installed in a space between the outer chamber and the inner chamber to remove heat of steam generated from the object to be dried by the microwave and to condense the condensed water.

Preferably, the heat exchanger is circulated with water or a refrigerant.

Preferably, the low-temperature vacuum drying apparatus using the microwave is provided with an inner lid for covering the upper end of the inner chamber, and the inner lid is openable and closable, and is opened and closed by interlocking with the lid of the outer chamber.

The microwave vacuum drying apparatus using microwave according to the present invention can dry objects to be dried in a short time with high energy efficiency, and thus can reduce carbon emission.

In addition, the drying object can be treated at a desired moisture content within about 2 hours, thereby minimizing protein denaturation and producing high-quality dried material.

1 is a cross-sectional view showing one embodiment of a drying apparatus for waste disposal according to the prior art;
2 is a schematic conceptual diagram of a preferred embodiment of the present invention.

Hereinafter, a low-temperature vacuum drying apparatus using microwaves according to the present invention will be described in more detail, and reference is made to the accompanying drawings. The drawings presented for the understanding of the present invention show only one practical example of the technical idea of the present invention, and the scope of the present invention is not limited thereto.

The low temperature vacuum drying apparatus using microwave according to the technical idea of the present invention can be used as a drying apparatus for various objects. That is, the object to be dried by the present invention is not particularly limited.

Typically, the microwave vacuum drying apparatus according to the present invention is suitable for use as a facility for drying various agricultural products. A variety of vegetables and fruits are produced every season, but these items, which are important for freshness, are often scrapped or damaged if they are not consumed on time. In other words, since most of the agricultural products have a short shelf-life, they must be stored for a long period of time after being harvested and dried.

In addition, the present invention can be utilized as a drying device for various aquatic products, such as sea cucumbers, which can produce high added value when dried in a circular shape.

In addition, the present invention can be used as a drying device for various kinds of sludge and food wastes.

FIG. 2 attached herewith shows a schematic diagram of a preferred embodiment of the present invention.

As shown, the present invention includes an outer chamber 100, an inner chamber 200, a microwave generator 300, a vacuum pump 400, and a heat exchanger 500.

A lid 10 is provided at an upper end of the outer chamber 100 and an inner chamber 200 is installed inside the outer chamber 100. The inner chamber 200 is fixedly installed at a predetermined distance from the outer chamber 100. The inner chamber 200 shields the microwaves from flowing out to the outside of the inner chamber 200.

In this embodiment, an inner chamber 200 made of a perforated plate or a mesh net is used. The hole size of the perforated plate or the mesh net may be selected in consideration of the frequency of the microwave.

A microwave generator 300 is provided which extends from the outside of the outer chamber 100 to the inside of the inner chamber 200 and emits the microwave into the inner chamber 200.

The microwave generator 300 may use a magnetron, and a microwave may be introduced into the inner chamber 200 using a waveguide.

An inner lid 20 is provided at an upper end of the inner chamber 200, and the inner lid 20 can be opened and closed. The microwave arriving at the inner chamber 200 does not escape to the outside of the inner chamber 200 and is used as a heat source for drying the object to be dried in the inner chamber 200.

Preferably, the inner lid 20 can be closed when the lid 10 is closed to seal the outer chamber 100.

In the present invention, a vacuum pump 400 is provided, and the vacuum pump 400 serves to discharge air remaining in the outer chamber 100 and the inner chamber 200. As is well known, the vaporization point of water varies with pressure, and the higher the degree of vacuum, the lower the vaporization point of water.

That is, the higher the vacuum, the faster the drying object can be dried at a lower temperature. The degree of vacuum formation through exhaust using the vacuum pump 400 may be as high as possible, but it is preferable to maintain a degree of vacuum of about 80% to 95%.

A low temperature vacuum drying apparatus using microwave according to the present invention is provided with a heat exchanger 500 and a heat exchanger 500 is installed in a space between the outer chamber 100 and the inner chamber 200.

That is, a separate inner chamber 200 is installed in the outer chamber 100. In a region where an inner space between the inner and outer surfaces of the outer chamber 100 and the inner chamber 200 is formed, a heat exchanger 500 ).

The heat exchanger 500 serves to circulate water or other refrigerant to draw the heat of steam and to induce condensation. The heat exchanger 500 is preferably formed into a coil shape so as to be disposed between the outer chamber 100 and the inner chamber 200, and a corrugated tube may be used to maximize the surface area for heat exchange.

Of course, water or refrigerant circulated through the heat exchanger 500 must be cooled through a cooling tower or other chiller, and a pump for circulating water or refrigerant is also provided.

The water vapor generated from the drying object due to the relatively low temperature heat exchanger 500 escapes the inner chamber 200 and condenses with water on the surface of the heat exchanger 500. Accordingly, the water vapor generated from the drying object by the microwave The drying time can be shortened because it quickly condenses out of the inner chamber 200 according to the pressure gradient due to the temperature difference.

In the present invention, since the microwave can not escape from the inner chamber 200 while being held in the inner chamber 200, the microwave does not affect the phase-changed water by the heat exchanger 500, Can be utilized to heat-evaporate the contained moisture. That is, unnecessary loss of the microwave can be eliminated as much as possible.

The microwave vacuum drying apparatus of the present invention as described above has an advantage that the drying object can be dried quickly while minimizing energy loss.

The present invention can be utilized for drying purposes of various agricultural and marine products, industrial raw materials and waste.

100: outer chamber 200: inner chamber
300: Microwave generator 400: Vacuum pump
500: heat exchanger
10: Lid
20: inner lid

Claims

An outer chamber having an openable and closable lid;
An inner chamber disposed inside the outer chamber, the inner chamber having a structure capable of passing water vapor while blocking external leakage of the microwave;
A plurality of microwave generators for emitting a microwave into the inner chamber;
A vacuum pump for evacuating the outer chamber and the inner chamber;
And a heat exchanger installed in a space between the outer chamber and the inner chamber to remove heat of steam generated from the object to be dried by the microwave and to condense the condensed material. .

The method according to claim 1,
Wherein the heat exchanger circulates water or a refrigerant.

3. The method according to claim 1 or 2,
Wherein the microwave-use low-temperature vacuum drying apparatus includes an inner lid that covers an upper end of the inner chamber, and the inner lid is openable and closable, and is opened and closed by interlocking with a lid of the outer chamber. Low temperature vacuum drying device using.