JP3293061B2 - Method and apparatus for drying object to be dried - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the drying of various foodstuffs such as cut flowers such as cut flowers and ornamental plants, leaf vegetables, root vegetables, stem vegetables and fruit vegetables, and tobacco leaves and the like. Drying of various plants, drying of seafood, drying of meat, drying of herbal medicine materials, drying of laundry such as medical laundry, industrial laundry, household laundry, drying of wood, drying of ceramic powder Drying of industrial parts, raw materials, products, etc.
The present invention also relates to a method and an apparatus for drying an object to be dried which are applied to various other various technical fields.

[0002]

2. Description of the Related Art Conventionally, for example, in the drying of dried flowers, cut flowers are set in a decompression tank, a predetermined degree of decompression is applied to the decompression tank, and controlled microwave heating is applied to the cut flowers. The cut flowers were dried by far-infrared heating (see Japanese Patent No. 2548090).

[0003]

However, when microwave power is large during heating and drying, the amount of heat for evaporating water droplets dropped on the inner surface of the decompression tank is too high because the speed of pushing out moisture from the dried material is too fast. Because of the shortage, water drops start to adhere to the inner surface of the decompression tank. In this case, even though the water content of the object to be dried is almost completely eliminated, the microwave is still transmitted because the microwave is also incident on the water droplet attached to the inner surface of the decompression tank. As a result, a small amount of microwaves are incident on the object to be dried, which has almost no residual moisture, so that a part of the object to be dried is burned. Also,
This is because microwaves act on water other than the object to be dried, and this is also a cause of great difficulty in controlling the drying of the object to be dried.

In Japanese Patent Publication No. 7-39322,
There is a statement that the inner wall surface and the inner atmosphere of the container of the vacuum device are heated with a far-infrared ray radiator to a temperature exceeding 50 ° C. and within 130 ° C. to evaporate the moisture of the fresh flowers. Although the technical idea of simultaneously heating the wall surface and the object to be dried is described, in the patent previously published by the present applicant, the speed of extruding moisture from the object to be dried to simultaneously operate microwave heating is also described. However, it is considered that a considerable amount of water adheres to the inner wall surface of the decompression tank. Therefore, it is difficult to quickly evaporate the water adhered to the inner surface using only far-infrared energy inside the decompression tank. This is because, when heating the moisture and the object to be dried attached to the inner surface of the decompression tank at the same time, it is sufficient to increase the energy of far infrared rays by a considerable amount. This is because all the thermal energy of the far-infrared rays is directed to the object to be dried, and the object to be dried is more likely to be overheated by far-infrared heating. In addition, since it is in the decompression tank, it is very difficult to immediately reduce the far-infrared energy once increased by temperature control.

[0005] The present invention has been made in view of the above points, and the object is not to evaporate the moisture attached to the inner surface of the decompression tank using only far-infrared energy. Basically, microwave heating and far-infrared heating are performed on the object to be dried, and the depressurizing tank itself is separated from the energy by an external heating means.
It is an object of the present invention to provide a method and an apparatus for drying an object to be dried, in which moisture attached to the inner wall surface of the decompression tank other than the object to be dried is subjected to an evaporative drying process by controlling the heating of the wall itself.

[0006]

According to a method of drying an object to be dried according to the present invention, an object to be dried is set in a decompression tank, and the decompression tank is pressure-controlled to one or more target decompression degrees, and A method for drying an object to be dried, wherein a controlled microwave heating and a far-infrared heating by a controlled far-infrared heater in a reduced-pressure tank are simultaneously performed on the object to be dried in a part or all of a total drying step, and the stainless steel is made of stainless steel. Composed of walls
The continuously or intermittently heated controlling wall of vacuum vessel itself externally, a stainless steel wall surface temperature of the vacuum vessel evaporation of water, by keeping constant the vaporization temperature, other than the material to be dried箇
The water such as water droplets on the stainless steel wall of the decompression tank is instantaneously evaporated and vaporized.

[0007] The apparatus for drying an object to be dried according to the present invention comprises:
Externally equipped with a microwave heating device with constant or variable input power and intermittent or continuous heating, and a control panel with adjustable heating and heating temperature in a decompression tank for setting the material to be dried Far-infrared heater set in a decompression tank
In a device provided with a control unit capable of simultaneously operating microwave heating and far-infrared heating, a stainless steel wall
Is provided with a mechanism for continuously or intermittently heating the decompression tank itself configured from the outside to a temperature at which water evaporates and evaporates, and a control unit therefor.

[0008]

[Action] The microwave heating when the water such as water droplets coming out from the material to be dried is adhered to a stainless steel wall surface of the vacuum vessel, by continuously heating control the vacuum vessel wall itself from the outside, the Decompression tank wall located in places other than dry matter
Water water drops above instantly evaporates, becomes possible to vaporize,
Overheating of the object to be dried by the microwave is eliminated, and a part of the object to be dried does not stick, so that the drying control accuracy of the object to be dried can be greatly increased. In addition, since the heating of the wall of the decompression tank itself is controlled from the outside, basically, far-infrared heating only needs to be performed on the object to be dried within the control range, and even from overheating by far-infrared heating. To be released.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a decompression tank, the wall surface 1a of which is water-resistant,
It is formed of stainless steel , which is a material having corrosion resistance and heat resistance.
Numeral 2 is a heater for heating the stainless steel wall 1a of the decompression tank 1 itself, and is usually a sheet heater 2 disposed in close contact with the back surface (outer wall surface with respect to the inner wall surface) of the wall surface 1a of the decompression tank 1 itself.
a is used. Although a silicon rubber heater is used as the sheet heater 2a, another sheet heater may be used. The planar heater 2a is a wall surface 1a of the decompression tank 1 itself.
If the temperature at which water adhering to the inner wall surface of the decompression tank 1 can be quickly evaporated and vaporized can be maintained without extending the entire surface of the back surface of the pressure-reducing tank 1 even if the entire surface is not stretched, various types of stretching methods may be used. Is also good. If a heat insulator is provided behind the sheet heater so that the heat is radiated to only one side, the heat can be radiated more efficiently. Although not shown in this example, a system in which the planar heater 2a or a heater having another structure is embedded in the wall instead of the rear surface of the wall surface 1a may be used.

Reference numeral 3 denotes a temperature controller for controlling the temperature of the heater 2 for heating the wall surface 1a of the decompression tank 1 itself. The controller 3 controls the temperature of the heater 2 to heat the wall surface 1a so as to maintain the temperature at which the water adhering to the inner wall surface of the decompression tank 1 is quickly evaporated and vaporized. In the drawing, reference numeral 4 denotes a far-infrared heater set in the decompression tank 1, which is usually set at four places on the ceiling, floor, and both side surfaces of the decompression tank 1. The degree of decompression is set through a decompression port 8 communicating with the decompression tank 1 by using a decompression valve 6 and a decompression adjustment valve 7 which are provided on the way to a vacuum pump 5 installed outside the decompression tank 1. Microwaves are injected into the decompression tank 1 via a microwave power unit 9 installed outside the decompression tank 1, an isolator 10, and a microwave inlet 12 in the decompression tank 1 via a bifurcated waveguide 11. Do more. Reference numeral 13 denotes a stirrer for performing uniform heating.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A silicon rubber heater, which is a kind of a planar heater 2a, is mounted on the back surface of a wall surface 1a of a decompression tank 1 so as to cover approximately 90% of the entire back surface of the wall surface 1a. Evaporation of water corresponding to the degree, temperature to evaporate,
For example, 60 ° C. was always maintained. Thus, even when moisture such as water droplets coming out of the material to be dried due to microwave heating adheres to the inner surface of the decompression tank, the decompression tank itself is continuously heated to cover the inner wall of the decompression tank. Moisture such as water droplets present in places other than the dried material instantaneously evaporates and evaporates, eliminating overheating of the object to be dried by microwave heating, and preventing the part of the object to be dried from sticking. The drying control accuracy of the dried product was greatly improved. In other words, as long as the water droplets are evaporated quickly and continuously and eliminated by the vacuum pump, the microwave transmission is stopped when the water content of the material to be dried becomes considerably low, so that overheating by microwave heating is avoided. be able to. In addition, since microwaves and far-infrared rays completely eliminate overwork due to heating of water droplets attached to the inner surface of the decompression tank, the accuracy of drying control of the object to be dried is significantly improved, and the entire drying process time is reduced by 30%. % Was able to be shortened.

[0012]

As can be seen from the above description, in the present invention, microwave heating and far-infrared heating are basically performed on the object to be dried inside the decompression tank , and the wall surface of the decompression tank itself has the energy. vacuum other than the material to be dried by heating control of the wall itself of the vacuum vessel by the heating means from separate external and
Excellent in that the water adhering to the tank wall surface can be quickly evaporated and dried , and the part to be dried does not stick.
Thus, a method and an apparatus for drying an object to be dried having the above-mentioned effects can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention.

FIG. 2 is a schematic explanatory view of a decompression tank used in the present invention.

[Explanation of symbols]

 1 Decompression tank1a Stainless steel wall
surface  Reference Signs List 2 heater 2a planar heater 3 temperature controller 4 far infrared heater 5 vacuum pump 6 pressure reducing valve 7 pressure reducing valve 8 pressure reducing port 9 microwave power unit 10 isolator 11 waveguide 12 microwave input
Mouth 13 stirrer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F26B 23/04 F26B 7/00 F26B 23/08

Claims (2)

(57) [Claims] An object to be dried is set in a decompression tank, the pressure in the decompression tank is controlled toward one or more target decompression degrees, and the object to be dried is controlled by microwave heating and controlled decompression. This is a method for drying the object to be dried, in which the far-infrared heating by the far-infrared heater in the tank is performed at the same time in part or all of the entire drying process, and is composed of stainless steel walls
Heating control is performed on the wall of the reduced pressure tank itself continuously or intermittently from the outside, and the temperature of the stainless steel wall of the reduced pressure tank is constantly maintained at the temperature at which water evaporates and evaporates .
A method for drying an object to be dried, characterized by instantaneously evaporating and vaporizing water such as water droplets on a stainless steel wall surface of the decompression tank . 2. A microwave heating device capable of intermittently or continuously heating a constant or variable input power to a decompression tank for setting an object to be dried, and a control capable of adjusting irradiation heating temperature. The panel was set in a decompression tank equipped with an outside
In a device provided with a far-infrared heater and provided with a control unit capable of simultaneously operating microwave heating and far-infrared heating ,
An apparatus for drying an object to be dried, comprising a mechanism for continuously or intermittently heating a decompression tank itself constituted by a wall made of stainless steel from the outside to a temperature at which water evaporates and vaporizes, and a control unit therefor.